Emp Diarrea

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July 2004Volume 6, Number 7

Authors

Michael D. Burg, MD, FACEP

Residency Program Director, Department of

Emergency Medicine, Onze Lieve Vrouwe Gasthuis

(Hospital), Amsterdam, The Netherlands.

Hoori Hovanessian, MD, FACEP

Assistant Clinical Professor, Department of

Emergency Medicine, UCSF–Fresno, University

Medical Center, Fresno, CA; Presbyterian

Intercommunity Hospital, Whittier, CA.

Peer Reviewers

Andy Jagoda, MD, FACEP

Vice-Chair of Academic Affairs, Department of Emergency Medicine; Residency Program Director;

Director, International Studies Program, Mount Sinai

School of Medicine, New York, NY.

Earl J. Reisdorff, MD, FACEP

Director of Medical Education, Ingham Regional

Medical Center; Associate Professor, Michigan

State University Emergency Medicine Residency,

Lansing MI.

CME Objectives

Upon completing this article, you should be able to:

1. construct a broad differential diagnosis for

diarrheal illness in adults and children;

2. describe aspects of a targeted history and physicalexamination for patients with diarrhea, including

indications for diagnostic testing;

3. identify ED patients at high risk for serious or

life-threatening diarrheal illnesses; and

4. describe treatment strategies for ED patients

with diarrhea.

Date of original release: July 1, 2004.

Date of most recent review: June 15, 2004.

See “Physician CME Information” on back page.

Associate Editor

Andy Ja goda, MD, FACEP,Vice-Chair of Academic

Affairs, Department of

Emergency Medicine;

Residency Program Director;

Director, International Studies

Program, Mount Sinai School of

Medicine, New York, NY.

Editorial Board

William J. Brady, MD, Associate

Professor and Vice Chair,

Department of Emergency

Medicine, University of Virginia,

Charlottesville, VA.

Judith C. Brillman, MD, Professor,


Medicine, The University of

New Mexico Health Sciences

Center School of Medicine,

Albuquerque, NM.

Francis M. Fesmire, MD, FACEP,

Director, Heart-Stroke Center,

Erlanger Medical Center;

Assistant Professor of Medicine,

UT College of Medicine,

Chattanooga, TN.

Valerio Gai, MD, Professor and

Chair, Department of Emergency

Medicine, University of Turin,

Italy.

Michael J. Gerardi, MD, FAAP,

FACEP, Clinical Assistant

Professor, Medicine, University

of Medicine and Dentistry of

New Jersey; Director, Pediatric

Emergency Medicine,

Children’s Medical Center,

Atlantic Health System;


Medicine, MorristownMemorial Hospital.

Michael A. Gibbs, MD, FACEP,

Chief, Department of

Emergency Medicine,

Maine Medical Center,

Portland, ME.

Gregory L. Henry, MD, FACEP,

CEO, Medical Practice Risk

Assessment, Inc., Ann Arbor,

MI; Clinical Professor, Department

of Emergency Medicine,

University of Michigan Medical

School, Ann Arbor, MI; Past

President, ACEP.

Francis P. Kohrs, MD, MSPH, Lifelong

Medical Care, Berkeley, CA.

Keith A. Marill, MD, Emergency

Attending, Massachusetts

General Hospital; Faculty, Harvard

Affiliated Emergency MedicineResidency, Boston, MA.

Michael S. Radeos, MD, MPH,

Attending Physician, Department

of Emergency Medicine, Lincoln

Medical and Mental Health Center,

Bronx, NY; Assistant Professor in

Emergency Medicine, Weill College

of Medicine, Cornell University,

New York, NY.

Steven G. Rothrock, MD, FACEP,

FAAP, Associate Professor of

Emergency Medicine, University

of Florida; Orlando Regional

Medical Center; Medical Director

of Orange County Emergency

Medical Service, Orlando, FL.

Alfred Sacchetti, MD, FACEP,

Research Director, Our Lady of

Lourdes Medical Center, Camden,

NJ; Assistant Clinical Professorof Emergency Medicine,

Thomas Jefferson University,

Philadelphia, PA.

Corey M. Slovis, MD, FACP, FACEP,

Professor of Emergency Medicine

and Chairman, Department of

Emergency Medicine, Vanderbilt

University Medical Center;

Medical Director, Metro Nashville

EMS, Nashville, TN.

Charles Stewart, MD, FACEP,

Colorado Springs, CO.

Thomas E. Terndrup, MD, Professor

and Chair, Department of

Emergency Medicine, University

of Alabama at Birmingham,

Birmingham, AL.

EMERGENCY MEDICINE PRACTICEA N E V I D E N C E - B A S E D A P P R O A C H T O E M E R G E N C Y M E D I C I N E

EMPRACTICE.NET

Diarrhea: Identifying Serious

Illness And Providing Relief It’s a stormy day, yet the ED is furiously busy. As you pick up your next patient’s chart,

you glance at the chief complaint—diarrhea. “Why would anyone come out on a day

like this, for something like that?” you wonder. Then your eye catches the patient’s age

(60) and vital signs—temperature, 38.7˚C (101.7˚F); pulse, 124 beats per minute;

respiratory rate, 24 breaths per minute; blood pressure, 102/50 mmHg. This man seems

a bit sicker than the run-of-the-mill diarrhea patient. A quick glance into his room

confirms your suspicion; he’s pale, sweaty, ill-looking. He clearly needs help. But is an

extensive work-up really going to be cost-effective—and won’t it keep you from treating

other patients in a timely manner? Besides, don’t most of these cases run their course

with a little help from fluids and symptomatic treatment?

DIARRHEA is a common condition that can stem from many causes.Fortunately, the care of the ED patient with diarrhea is usually straightfor-ward—a targeted history and physical examination, followed by symptomatic

remedies. However, the temptation to dismiss a case as “just diarrhea” can be

quite dangerous, as serious disease processes can present with diarrhea as the

chief complaint. Some patients require more systematic investigation or even

hospitalization. Clinical judgment based on the current evidence can help guide

a cost-effective work-up of patients with diarrhea that will identify patients

with more severe etiologies or at risk for complications.

Critical Appraisal Of The Literature

Given that diarrhea is such a ubiquitous part of the human condition, it’s notsurprising that the literature on the subject is truly voluminous. Thousands of

studies address the epidemiology, etiology, pathophysiology, evaluation,

treatment, differential diagnosis, and other features of patients with diarrhea.

Thankfully, a number of well-done reviews, meta-analyses, and position

statements from expert medical organizations condense the findings, making

the job of the practicing emergency physician caring for patients with diarrhea

much easier.1-19

In general, the preponderance of evidence tends to support the following

practices in patients with diarrhea:


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Emergency Medicine Practice 2 EMPractice.net • July 2004

• Evaluating the patient: The presence of a dry axilla

supports the diagnosis of hypovolemia, and moist

mucous membranes and a tongue without furrows

argue against it. In adults, the capillary refill time and

poor skin turgor have no proven diagnostic value.3

Acute body weight changes provide the best measures

of dehydration in children. Mucous membrane

hydration, capillary refill time, absence of tears, and

alterations in mental status are the next best associated

measures.4 Important features of the history include

how the illness began; stool characteristics (frequency

and quantity); travel history; occupation; day care

center attendance or nursing home residence; whether

the patient has ingested raw or undercooked meat, raw

seafood, or raw milk; whether the patient’s contacts are

ill; the patient’s sexual contacts, medications, and other

medical conditions, if any.2,5 Red-flag findings include

severe dehydration, bloody or febrile diarrhea, or

illness in infants, elderly, or immunocompromised

patients.5 Serial evaluations over several hours can

improve the diagnostic accuracy in patients in whom

the etiology is unclear.1

• Laboratory testing: Routine testing for specific

pathogens is not recommended.4 Reserve laboratory

testing and stool cultures for select circumstances.

Criteria vary but often include bloody diarrhea,

weight loss, diarrhea leading to dehydration, fever,

neurologic involvement, sudden onset of severe

abdominal pain, persistent (> 7 days) diarrhea, or

possible community-acquired diarrhea, traveler’s

diarrhea, or nosocomial diarrhea.2,5 Maintain a lower

threshold for ordering if the patient is pediatric,

elderly, or immunocompromised.2

• Rehydration: Initiate rehydration (oral wheneverpossible).5 In children, clear liquids are not recom-

mended as a substitute for oral rehydration solutions or

regular diets to prevent or treat dehydration.4

• Diet: Refeeding of the usual diet at the earliest opportu-

nity should be encouraged to prevent or limit dehydra-

tion. Very frequent (e.g., every 10-60 minutes), small

feedings may be better tolerated if vomiting is present.

The BRAT diet (bananas, rice, applesauce, and toast)

affords no advantage unless these foods are part of the

regular diet.4

• Medications: Antibiotic therapy can reduce illness

duration by one or two days in most cases. Criteria forempiric antibiotic therapy vary, but consideration of

risks must be weighed against any potential benefits. In

children, antimicrobial therapies are recommended

only when special risks or evidence of serious bacterial

infection is present.4 Institute selective therapy for

traveler’s diarrhea, shigellosis, and Campylobacter

infection.5 Avoid administering antimotility agents with

bloody diarrhea or proven infection with Shiga toxin-

producing Escherichia coli.5 Anti-diarrheal agents and

antiemetics are not recommended for use in children

with acute gastroenteritis.4

Etiology, Epidemiology, And Pathophysiology

Etiology

Diarrhea is a change in normal bowel movements character-

ized by an increase in the water content, volume, or

frequency of stools. Fluid secretion into the gut and

increased gut motility together produce both the increased

stooling frequency and the increased stool liquidity.16,20 The

passage of more than 200 grams of stool per day is consid-

ered to be diarrhea; two to three bowel movements per dayis the upper limit of normal.

An episode of diarrhea lasting 14 days or less is

generally defined as “acute diarrhea,” while “persistent

diarrhea” refers to episodes lasting longer than 14 days.

“Chronic” diarrhea is generally defined as diarrhea that

lasts more than 30 days.

Epidemiology

Virtually every human being experiences diarrhea at some

point. Causes may range from the mild to the life-threaten-

ing, although the clinical course is generally brief and self-

limited in developed nations. However, worldwide,

diarrheal illnesses are the second most common cause of

death and the leading cause of death in children.21

Diarrhea is a common cause of morbidity even in the

United States. The number of hospital admissions due to

gastroenteritis in the United States is estimated to be 450,000

per year.20 Additionally, the U.S. prevalence of chronic

diarrhea approaches 5%.22

Pathophysiology

Diarrhea is broadly categorized as one of two types—either

secretory or osmotic.

The poorly named secretory diarrhea actually occurs

due to abnormal electrolyte transport across the intestinalepithelial cells. Increased secretion and/or decreased

absorption result. The diarrhea is not related to the intestinal

contents and therefore typically does not stop with fasting.

Infection (e.g., cholera) is the most common cause of

secretory diarrhea. The fluid losses can be enormous.

Osmotic diarrhea results from the presence of non-

absorbable solute that exerts an osmotic pressure effect

across the intestinal mucosa, resulting in excessive water

output. Because the diarrhea is caused by the solute, it tends

to stop during fasting. Sorbitol, a poorly absorbed sugar, is

capable of causing osmotic diarrhea.20

Another way that diarrhea is commonly classified is as

infectious vs. noninfectious or inflammatory vs. non-inflammatory. Symptoms such as fever, bloody diarrhea,

and severe cramping suggest an invasive bacterial pathogen

such as Shigella, Salmonella, Yersinia, or Campylobacter. The

presence of nausea and vomiting strongly suggests a viral

agent, and prior antibiotic use suggests possible Clostridium

difficile enteritis. Absence of these factors suggests a non-

infectious cause. Inflammatory diarrhea can be bloody and

associated with fever and abdominal cramps. The causes

can be infectious or non-infectious. Non-inflammatory

diarrhea tends to be watery and can be associated with

nausea, vomiting, and abdominal cramps.


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3 Emergency Medicine PracticeJuly 2004 • EMPractice.net

Differential Diagnosis

The differential diagnosis of diarrhea with abdominal pain

is vast. While patients who present with vomiting, diarrhea,

and abdominal cramps and who have benign abdominal

examinations may seem like clear-cut cases of gastroenteri-

tis—and most patients will respond well given rehydration

and antiemetics—it is important to be aware that the

differential diagnosis includes more severe etiologies that

require different management approaches. (See Table 1.)

Infectious Enteritis

Infectious causes of diarrhea are commonly seen in the ED.

Ingestion of contaminated food or water is the typical

culprit; recent travel, exposure to other ill persons, recent

hospitalization, child care center attendance, and nursing

home residence should all raise the index of suspicion. (See

Table 2 on page 4.)

Common bacterial agents include Campylobacter,

Salmonella, and Shigella species, as well as E. coli. Viral

infections may be caused by rotavirus, Norwalk virus,

cytomegalovirus, herpes simplex virus, and viral hepatitis.

In developed countries, parasitic diarrhea is generally only a

concern among travelers and those with prolonged diar-

rhea. Parasites that cause diarrhea include Giardia lamblia,

Entamoeba histolytica, and Cryptosporidium.2

Signs and symptoms such as bloody diarrhea, weight

loss, diarrhea leading to dehydration, fever, prolonged

diarrhea (3 or more unformed stools per day, persisting

several days), neurologic involvement (such as paresthesias,

motor weakness, cranial nerve palsies), and/or severe

abdominal pain may suggest infectious causes and drive the

need for laboratory testing, especially in young, elderly, or

immunocompromised patients.2

Irritable Bowel Syndrome

Patients with irritable bowel syndrome can have abdominal

pain or discomfort, constipation, diarrhea, or an alternating

course of constipation and diarrhea. A mucoid rectal

discharge is present in about half of afflicted patients.23

Evaluation of these patients fails to produce an organic basis

for the disease; patients do not experience weight loss, fever,

or rectal bleeding. While symptoms vary from person to

person, irritable bowel syndrome is typically characterized

by abdominal pain or discomfort for at least 12 weeks out of

the previous 12 months; abdominal pain that is relieved by

having a bowel movement; and changes in frequency or

appearance of stool when an episode starts. Eliciting a

history suggestive of irritable bowel syndrome requires

referral to exclude more serious disease processes.

Table 1. Typical Characteristics Of Different Etiologies Of Diarrhea.

Infectious

Viral gastroenteritis

Diarrhea with aches, chills, cold symptoms, nausea or

vomiting; history suggesting recent consumption of

contaminated food or exposure to other ill persons,

especially day care; with or without fever

Bacterial diarrhea or GiardiaDiarrhea, history suggesting recent consumption of contami-

nated food, with or without fever (see Table 2 on page 4)

Traveler’s diarrhea

Recent foreign travel, prolonged illness (see also Table 3 on

page 6)

Functional bowel disorders

Irritable bowel syndrome

Variable symptoms but prolonged course; bowel move-

ments that alternate between constipation and diarrhea,

especially if episodes are related to stress

Intestinal obstruction

Severe abdominal pain along with nausea, vomiting, anddiarrhea

Fecal impaction/other blockage

Chronic constipation followed by recent watery diarrhea

Inflammatory

Inflammatory bowel disease (includes Crohn’s disease and

ulcerative colitis)

Frequent bowel movements mixed with blood or mucus

Appendicitis

Vomiting that follows abdominal pain, small amounts of

watery diarrhea (compared to the voluminous amounts

produced as a consequence of gastroenteritis), mild or

absent fever

Vascular

Ischemic bowel disease

Diarrhea, severe abdominal pain, older patient, history of peripheral vascular disease

Malabsorption

e.g., celiac disease or lactose intolerance

Diarrhea, gas, bloating, and stomach pains that seems to be

triggered by certain foods

Medications

Recent new medicine, especially antibiotics, high blood

pressure medications, cancer drugs/radiation therapy,

some herbal medicines

Toxins

Radiation enteritis

Tenesmus, bleeding, and diarrhea stemming from malab-

sorption; can persist for two or three months after

treatment cessation

Arsenic, mushroom poisoning, pesticides, etc.

Varies; usually diarrhea is one of several symptoms

Other systemic conditions

e.g., food allergies, colon cancer, hyperthyroidism

Typically a longer course plus other suggestive symptoms;

see also Table 3 on page 6


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Inflammatory Bowel Disease

Inflammatory bowel disease is a general term that refers to

illnesses that cause chronic inflammation in the intestines,

typically causing diarrhea and abdominal cramps. The two

major types of inflammatory bowel disease are Crohn’s

disease and ulcerative colitis.

Crohn’s disease is a chronic inflammation of the

intestines that is usually confined to the ileum. It is charac-

terized by abdominal cramps or pain, diarrhea (sometimes

bloody), fever, and anorexia. The clinical course may be

erratic, with frequent relapses interspersed with periods of

symptom remission.24

Ulcerative colitis, which is also a chronic inflammatory

disease, is confined to the colon and rectum. Patients with

mild disease may present with fewer than four bowel

movements per day, whereas patients with severe disease

may experience more than six bowel movements per day

along with weight loss, fever, and anemia. While the

diarrhea is often bloody, many patients do not have grossly

bloody stools, even with exacerbations. It too may be

characterized by periods of remission.

A documented history of inflammatory bowel diseasewill aid in providing patients appropriate evaluation and

treatment. Some patients, however, will have episodic

symptoms for years before being correctly diagnosed.

Eliciting a family history of inflammatory bowel disease or

other risk factors for it will allow rapid evaluation of this

condition by referral to a gastroenterologist.24 The diagnosis

rests on the clinical history, stool studies to exclude infec-

tion, and colonoscopy to determine the presence and extent

of disease.

Ischemic Bowel Disease

Ischemic bowel disease should be considered in adults with

abdominal pain, especially if they are older than 50 years or

have a history of peripheral vascular disease. Most patients

with acute mesenteric ischemia will present with severe

abdominal pain, although there can be a paucity of physical

findings. The abdominal pain may be followed by a rapid

and forceful bowel movement.25 Other patients may have

chronic mesenteric ischemia with chronic intermittent

abdominal pain of up to several months’ duration (intestinal

angina) followed by an acute attack of pain. These patients

may experience weight loss, as well as occasional diarrhea

and bloating.26 Occult fecal blood is present in up to 75% of

patients.27 Bloody diarrhea may occur in those with ischemic

colitis (inflammation of the colon caused by insufficient blood flow to the colon); those with small bowel ischemia

will have voluminous diarrhea.28 Individuals at increased

risk for ischemic bowel disease include patients with

Table 2. Agents Causing Infectious Diarrhea And Their Associated Symptoms.

Campylobacter jejuni Symptoms: fever, headache and muscle pain followed by

diarrhea (sometimes bloody), abdominal pain and nausea

that appear 2-5 days after eating; may last 7-10 days.

Clostridium perfringensSymptoms: diarrhea and gas pains may appear 8-24 hours

after eating; usually last about one day, but less severesymptoms may persist for 1-2 weeks.

Escherichia coli 0157:H7Symptoms: diarrhea or bloody diarrhea, abdominal cramps,

nausea, and malaise; can begin 2-5 days after food is eaten,

lasting about eight days. Very young patients can develop

hemolytic uremic syndrome, which causes acute kidney

failure. A similar illness, thrombotic thrombocytopenic

purpura, may occur in older adults.

Listeria monocytogenesSymptoms: fever, chills, headache, backache, sometimes

abdominal pain and diarrhea; onset from 7-30 days after

eating, but most symptoms are reported 48-72 hours after

consumption of contaminated food; primarily affectspregnant women and their fetuses, newborns, the elderly,

people with cancer, and those with impaired immune

systems; can cause fetal and infant death.

Salmonella (many types)Symptoms: stomach pain, diarrhea, nausea, chills, fever, and

headache usually appear 8-72 hours after eating; may last

1-2 days; all age groups are susceptible, but symptoms are

most severe for the elderly, the infirm, and infants.

Shigella (many types)Symptoms: disease referred to as “shigellosis” or bacillary

dysentery. Diarrhea containing blood and mucus, fever,

abdominal cramps, chills, and vomiting; 12-50 hours from

ingestion of bacteria; can last a few days to two weeks.

Staphylococcus aureusSymptoms: severe nausea, abdominal cramps, vomiting, and

diarrhea occur 1-6 hours after eating; recovery within 2-3

days—longer if severe dehydration occurs.

Vibrio parahaemolyticusSymptoms: Diarrhea, abdominal cramps, nausea, vomiting,

headache, fever, and chills; onset four hours to four days

after eating; lasts about 2.5 days.

Cyclospora cayetanensisSymptoms: Nausea, vomiting, loss of appetite, and diarrhea;

onset within two days; lasts one week to two months.

Cryptosporidium parvumSymptoms: Profuse watery diarrhea, abdominal pain, appetite

loss, vomiting, and low-grade fever, onset within 1-12 days.

Giardia lamblia

Symptoms: Sudden onset of explosive watery stools,abdominal cramps, anorexia, nausea, and vomiting; onset

within 1-3 days.

Viral gastroenteritis from Norwalk and Norwalk-like virusesSymptoms: Nausea, vomiting, diarrhea, abdominal pain,

headache, and low-grade fever; onset within 1-2 days; lasts

about 36 hours.

Adapted from: U.S. Food and Drug Administration Center for FoodSafety and Applied Nutrition Web site (http://www.cfsan.fda.gov/~dms/qa-fdb12.html, http://www.cfsan.fda.gov/~dms/unwelcom.html).


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hypovolemia, sepsis, cardiac arrhythmias, congestive heart

failure, and those using vasoconstrictive medications or

drugs (e.g., digitalis, pseudoephedrine, cocaine, amphet-

amines).29 Ischemia may progress to infarct unless detected

and treated early.

Radiation Enteritis

Radiation therapy is used to treat a number of urologic,

gynecologic, and colorectal cancers. During the radiation

treatment period, most patients experience tenesmus,

bleeding, and diarrhea.30 Malabsorption from mucosal

damage and bacterial overgrowth are two factors that

contribute to these symptoms.26 Symptoms can start within

hours of initial treatment and usually resolve two or three

months after treatment cessation,30 although some patients

may develop chronic problems necessitating surgery. The

rectum is the most commonly inflamed site given its

proximity to the irradiated tissue; the terminal ileum can

also be irradiated in patients undergoing treatment for

pelvic malignancies.

Treatment of acute radiation enteritis involves tempo-

rary discontinuation of radiation therapy, selective intrave-nous fluid administration, and antimotility medications.

Sucralfate may ameliorate the symptoms of radiation

enteritis. In one double-blind placebo-controlled trial of

patients with prostate or bladder cancer randomized to

receive either oral sucralfate or placebo, those patients

receiving sucralfate had improvement in the frequency and

consistency of bowel movements, and fewer patients

required treatment with anti-diarrheal preparations.31

Appendicitis

Patients with appendicitis can have vomiting as well as

loose stools. Rectal irritation by an inflamed pelvic appendix

can produce small amounts of watery diarrhea, as com-pared to the voluminous amounts produced as a conse-

quence of gastroenteritis.32 In Rothrock et al’s study of 181

children younger than 13 years who were ultimately found

to have appendicitis, 27% were initially misdiagnosed.

Patients in this group were more likely to be younger, have

vomiting before pain, and have diarrhea (in addition to

constipation, dysuria, and upper respiratory tract symp-

toms).33 A retrospective case series review of 63 children

younger than 3 years ultimately diagnosed with appendici-

tis found that 57% were initially misdiagnosed; diarrhea

was commonly reported.34 A retrospective review of 87

patients with appendicitis revealed that six patients (7%)

required more than one ED visit before their diagnosis wasestablished. The initial diagnosis in two of these patients

was gastroenteritis. These six patients were more likely to

have a normal appetite, to have diarrhea, and to be afe-

brile.35 While most patients with appendicitis present with

right lower quadrant abdominal pain, 15% of appendices

are in atypical locations, causing pain in locations other than

the right lower quadrant.32 Gastroenteritis can present with

fevers higher (>103˚F) than those seen with appendicitis,

and in general, vomiting and diarrhea precede abdominal

pain, whereas vomiting follows abdominal pain in appendi-

citis. Because appendicitis will steadily worsen, while

uncomplicated gastroenteritis generally resolves with fluids,

a period of observation can help identify patients with

appendicitis if the diagnosis is unclear.

Miscellaneous Causes

Many other entities should be considered in the differential

diagnosis of diarrhea, including melena, laxative abuse,

partial bowel obstruction, various malabsorption syn-

dromes (e.g., Whipple’s disease, small bowel bacterial

overgrowth, celiac sprue), food allergy, rectosigmoid

abscess, colon cancer, diverticulitis, hyperthyroidism, and

pernicious anemia. Many medications (as well as herbal

remedies) can cause diarrhea. In pediatric patients, age-

appropriate problems such as intussusception and Meckel’s

diverticulum should be considered in the differential

diagnosis of diarrhea. Uncommon causes of diarrhea

include mushroom poisoning, ciguatera fish poisoning,

arsenic ingestion, and exposure to pesticides, sodium

fluoride, thallium, or zinc. In most of these cases, diarrhea is

part of a symptom complex, and other suggestive elements

of the history are present.

Prehospital Care

Initial prehospital assessment should focus on the patient’s

vital signs and mental status. Transport hemodynamically

stable patients without further intervention. Follow local

EMS protocols for hypotension/shock for patients who are

hemodynamically unstable; usually, this includes establish-

ing at least one large-bore intravenous line and infusing

crystalloid solution and expediting the transport of unstable

patients for further evaluation and care.

While gastrointestinal infections may be caused by a

variety of agents, including bacteria, viruses, and protozoa,

only a few agents have been documented in person-to-person transmission. Generally, adherence to either stan-

dard or contact precautions will minimize the risk of

transmitting enteric pathogens.36

Emergency Department Evaluation

HistoryHistory Of Present Illness

Obtaining a thorough history is crucial. Certain issues

are important to address during patient assessment.

They include:

• Type and volume of stools: Also note whether the

stools contain any blood. (Note that melena may not be perceived by the patient to be “ bloody”; ask about

blackened stools as well. See also the March 2004

issue of Emergency Medicine Practice, “Gastrointestinal

Bleeding: An Evidence-Based ED Approach To

Risk Stratification.”)

• Associated symptoms such as nausea, vomiting,

abdominal pain, fever, and tenesmus: When vomiting

is a prominent feature of the patient’s symptoms,

viruses are the more likely etiologic agents.12,37 Fever

greater than 38.5˚C (101.3˚F) is usually associated with

intestinal inflammation due to invasive bacteria (e.g.,


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Shigella, Salmonella, or Campylobacter species), enteric

viruses, or toxin-induced damage due to Clostridium

difficile or Entamoeba histolytica.37

• Character and location of any abdominal pain: Pain is

common in patients with mesenteric ischemia, inflam-

matory bowel disease, and irritable bowel syndrome.22

• Duration of symptoms: Symptom duration can help

narrow the differential diagnosis. Viral gastroenteritis

usually lasts 12-60 hours.2 Thus, it is less likely that

diarrhea lasting more than a couple of days or so is

viral. Diarrhea lasting greater than two weeks often has

a different etiology (see Table 3) than diarrhea that has

been present for less than two weeks.37

• Weight loss: Determine whether the patient has lost

weight. Patients with diarrhea may have weight loss

because of both increased output and reduced intake.

Substantial weight loss is more likely due to ischemia,

neoplasm, or malabsorptive syndromes.22 Weight loss

may be an indicator of dehydration in children.

• Indicators of dehydration: Asking about urine output,dizziness, thirst, and syncope—as well as asking

family members or prehospital personnel about altered

mental status—is useful in assessing the patient’s

volume status.

• Epidemiological risk factors: Further questions should

focus on the patient’s recent diet, and specifically

whether there has been any ingestion of seafood, raw

or undercooked meat, eggs, or milk products. In

addition, ask about recent foreign travel or local

outings involving lake or stream swimming or visits to

a farm, ill contacts, group living arrangements (e.g.,

nursing home, college dormitory) or day care atten-

dance, and occupational hazards such as food handling

or working with animals.

Past Medical History

The patient’s past medical history also provides essential

information for the management of patients with diarrhea.

Are you treating an otherwise healthy 20-year-old woman, a

patient with HIV/AIDS, or a 70-year-old diabetic man with

a history of congestive heart failure taking numerous

medications? Is the patient undergoing cancer treatment?

Consider pathogens that affect immunosuppressed hosts in

patients receiving chemotherapy. Acute radiation enteritis is

a concern in those who have undergone radiation treatment

within the past six weeks. Inquire about other gastrointesti-

nal ailments such as Crohn’s disease or ulcerative colitis.

Medications

Obtaining a history of medication use—specifically includ-

ing prescription, over-the-counter, and herbal prepara-

tions—is important, since many can cause diarrhea. Some of

the more common offenders include laxatives, antibiotics,

colchicine, and magnesium- or calcium-containing antacids.If there is a history of antibiotic use within the past three

months, C. difficile-induced diarrhea is an important

consideration.38 Diabetics using a relatively new class of

hypoglycemic medications known as alpha-glucosidase

inhibitors (e.g., acarbose, miglitol) may develop abdominal

pain, bloating, and diarrhea. Artificial sweeteners contain-

ing sorbitol or mannitol are poorly absorbed and may cause

diarrhea. Patients on enteral tube feedings may also develop

diarrhea.28 The elderly are more likely to be on multiple

medications and may be more susceptible to adverse effects.

Review Of Systems

A brief review of systems is additionally helpful. Apatient who is currently menstruating may have guaiac-

positive stools secondary to stool sample contamination

from menstrual blood. The patient’s pregnancy status is

important for antibiotic selection, use of medications

for symptomatic treatment of the diarrhea, and decisions

about managing her hemodynamic status. Ask the patient

about the ability to get to the bathroom on time. Some

individuals complain of diarrhea when the real problem

is fecal incontinence.

Social History

The patient’s occupational history may be relevant if they

work as a veterinarian, food handler, or day care center ornursing home employee. The patient’s sexual preference

and whether they engage in receptive anal intercourse

should be ascertained as this may expand the differential

diagnosis to include AIDS-associated diarrhea as well as

proctitis secondary to sexually transmitted diseases.

Inquire about alcohol and drug use. Patients who abuse

alcohol may present with various abdominal complaints,

including diarrhea and melena. Opioid withdrawal

frequently involves nausea, vomiting, and diarrhea. Patients

with eating disorders or those attempting to lose weight

should be questioned about laxative abuse.

Table 3. Common Causes Of DiarrheaPersisting Longer Than Two Weeks.

ParasitesCryptosporidium parvum, Cyclospora cayetanensis, Entam-

oeba histolytica, Giardia lamblia, microsporidia

BacteriaCampylobacter, Clostridium difficile, Escherichia coli, Listeria

monocytogenes, Salmonella enteritidis, Shigella

Viral infectionsHIV

MedicationsAntibiotics, high blood pressure medications, cancer drugs/

radiation therapy

Noninfectious food sourcesFood allergies; certain food additives (sorbitol, fructose, and

others) are also implicated

Other systemic conditionsDiabetes, thyroid and other endocrine diseases; malignan-

cies/tumors; previous surgery of the abdomen or gas-

trointestinal tract; conditions causing reduced blood flow

to the intestine such as ischemic bowel disease


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Physical Examination

Primary Survey

While patients with a chief complaint of diarrhea rarely

present with an imminent life threat, the initial assessment

of any ED patient should include a rapid assessment of

the ABCs. Hypovolemic or septic shock may require

the patient’s airway to be secured and the patient to

be ventilated.

Secondary Survey

A secondary survey allows for further assessment of the

patient’s volume status as well as the presence or absence of

systemic toxicity. Is the patient febrile? Is postural hypoten-

sion present? Are the mucus membranes dry? For infants, is

the anterior fontanelle sunken? Is the pediatric patient

producing any tears when crying? Note the patient’s skin

turgor, jugular venous pressure, capillary refill, and the

presence or absence of sunken eyes. Also, evaluate the

patient’s mental status. Is the patient awake, alert, and able

to answer questions? Is the patient lethargic or completely

unresponsive? Other features of diagnostic significance

include the presence of flushing or rashes on the skin,mouth ulcers, thyroid masses, wheezing, arthritis, heart

murmurs, hepatomegaly or abdominal masses, ascites,

and edema.16

The abdominal examination should include ausculta-

tion of bowel sounds as well as the presence or absence

of tenderness or peritoneal signs. A rectal examination

can determine whether the stools are grossly bloody,

melanotic, or guaiac-positive. Given the fact that melanotic

stools are usually liquid, the patient may refer to this type

of stool simply as “diarrhea.” Thus, a rectal examination

may play an important role in assessing the nature of the

stools. Selected female patients may require a pelvic

examination depending on the degree and location of their abdominal pain.

Diagnostic Studies

Blood Tests

Routine CBC counts or chemistry panels are unnecessary in

most patients since diarrhea is a self-limited problem in

most cases. A chemistry panel may reveal an electrolyte

imbalance or the degree of dehydration in systemically ill

patients, or in those with severe or persistent diarrhea. In

patients with bloody diarrhea, obtain a CBC and platelet

count to exclude hemolytic uremic syndrome. (Hemolytic

uremic syndrome is discussed in further detail in the sectionon pediatric patients later in this article.) Eosinophilia on the

leukocyte differential can point to food allergy, collagen-

vascular diseases, neoplasm, parasitic infections, or eosino-

philic gastroenteritis or colitis.22 Such diagnostic testing

should be reserved for select cases in which clinical or

epidemiologic factors or disease severity suggest their

need.5 Unfortunately, the literature does not provide clear-

cut indications for such testing.

Fecal Leukocyte/Lactoferrin Testing

Fecal leukocytes and fecal lactoferrin testing can provide

more timely results and are therefore more useful in the ED

setting than stool cultures in identifying causes of inflamma-

tory diarrhea. A selective approach to fecal leukocyte/

lactoferrin testing in patients with diarrhea is recom-

mended, yet the precise approach remains a matter of

dispute. Community-acquired or traveler ’s diarrhea,

nosocomial diarrhea, and diarrhea persisting more than

seven days have been suggested by the Infectious Diseases

Society of America as indications for testing.5 The utility of

these tests lies in helping to determine whether antibiotic

treatment is indicated.37

Occult blood, fecal leukocytes, and fecal lactoferrin are

often found in the stools of patients with inflammatory

diarrhea. The most common pathogens in patients with a

positive test result include Shigella, Salmonella, Campylobacter,

Aeromonas, Yersinia, non-cholera Vibrio species,40,41 and

Clostridium difficile.42

Fecal leukocytes are generally seen in the stool of

patients with shigellosis, salmonellosis, Campylobacter,

enteroinvasive E. coli, enterohemorrhagic E. coli, or staphylo-

coccal enterocolitis.43 Other conditions in which fecal

leukocytes may be seen include Entamoeba histolyticaenteritis, Crohn’s disease, ulcerative colitis, and

pseudomembraneous colitis.44

Lactoferrin is a protein found in leukocytes. The fecal

lactoferrin assay can measure levels of lactoferrin released

from damaged or deteriorated leukocytes in stool speci-

mens.43 Although more research is needed, some studies

indicate that fecal lactoferrin is more sensitive than fecal

leukocytes or occult blood as a screening tool for detecting

invasive pathogens45,46 as well as for detecting other causes

of inflammatory diarrhea such as ulcerative colitis and

Crohn’s disease.47,48 The test is slightly costlier than fecal

leukocyte testing, but it is quicker and easier to perform and

is not limited by the need for a fresh stool specimen.49Guaiac-positive stools, as well as the findings of fecal

leukocytes and fecal lactoferrin, are all predictive of finding

an identifiable bacterial pathogen on stool culture.37 In one

prospective study of 873 patients, stool cultures were

ordered in 549 episodes (62.6%), most frequently for patients

with fever, more than 10 stools per day, or visibly bloody

stools. Enteropathogens were identified in 168 episodes

(30.6%).39 In another well-designed study of 1040 patients,

the absence of occult blood in the stool was a reliable

indicator for a lack of enteroinvasive bacteria.40

Stool Culture

While readily obtainable tests such as heme- or leukocyte-positive stools can provide the ED practitioner with

valuable information, stool cultures may be advisable under

certain circumstances.

The use of antibiotics in certain cases of bacterial

diarrhea can produce undesirable outcomes, so determining

the causative agent via stool cultures can be helpful.

For instance, treatment of salmonellosis can prolong the

carrier state and lead to a higher clinical relapse rate. 28

The likelihood of hemolytic uremic syndrome in patients

infected with E. coli 0157:H7 is increased with the use of

antibiotics.50 Empiric antibiotic use may increase the risk


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of C. difficile colitis.

Determination of antimicrobial susceptibility is also

important given the emergence of resistance to some

commonly used antibiotics. Finally, negative stool culture

results may be important prerequisites for the diagnosis of

certain ailments such as inflammatory bowel disease.

Stool cultures can also play a role in identifying agents

that have significant public health consequences. An

outbreak of illness due to Salmonella enteritidis serves to

illustrate this point. The state public health laboratory in

Minnesota received a higher-than-expected number of

reports of Salmonella isolates from local clinical laboratories

in 1994. These reports ultimately led to the detection of a

nationwide outbreak of Salmonella enteritidis infection due to

contaminated ice cream that had been widely distributed

(with patients afflicted in 41 states). An estimated 220,000

people were affected by this outbreak.51 Elimination of the

contaminated product from the market potentially pre-

vented the spread of this infection to thousands of others.

These preventive measures were possible because stool

cultures were obtained on the first patients who presented

to their physicians with diarrhea.While these examples provide compelling evidence for

obtaining stool cultures on patients with diarrhea, the yield

on routinely obtained stool cultures is low. In six studies

conducted between 1980 and 1997, stool cultures were

positive in 1.5%-5.6% of cases.5 This translates to a cost of

$952-$1200 for each positive culture obtained. Interestingly,

in the study with a positive culture yield of 5.6%, 63% of the

patients had grossly bloody stools, while 91% presented

with a history of bloody diarrhea.52

Therefore, experts recommend restricting the use of

stool cultures. In patients in whom vomiting is a prominent

feature of their disease, viral agents are the likely etiology

and stool cultures will have a low yield. Proposed criteriathat suggest a higher yield from stool cultures include

history of bloody stools (grossly bloody or heme-positive

stools) or stools containing leukocytes or lactoferrin;

immunocompromised patients; fever higher than 38.5˚C

(101.3˚F); systemic illness or an illness that is clinically

severe or persistent; and patients with severe abdominal

pain.2,28,53 Selective cultures can be considered in specific

circumstances such as bloody diarrhea in afebrile patients

with a history of ingestion of unpasteurized juice or milk or

undercooked beef (suggests enterohemorrhagic E. coli);

patients who have consumed shellfish within 72 hours of

the onset of illness (suggests Vibrio parahemolyticus); and

patients who have been on antibiotics within the past three

months (suggests C. difficile).

Ideally, stool samples should be sent for culture within

two hours after passage to allow for detection of certain

pathogens that perish quickly. If the patient is unable to

provide a stool sample, a rectal swab can be brought to the

lab in transport media and then cultured.28

Routine stool cultures in most laboratories will identify

Shigella, Campylobacter, and Salmonella.2 (In patients who

develop diarrhea after three days of hospitalization, C.

difficile testing will have a higher yield (15%-20%), whereas

standard stool cultures will have poor yields.28)

Stool Testing For Parasites

In developed countries, testing for ova and parasites in

patients with acute diarrhea is rarely indicated.54 Cases in

which testing for ova and parasites may be appropriate

include patients who present with diarrhea lasting more

than 14 days, the immunocompromised, and patients who

have not responded to antimicrobial therapy.2 Other

situations in which to consider ova and parasite testing

include a community outbreak of diarrhea with a suspectedwaterborne cause, exposure to infants at a day care center,

patients with a history of travel to endemic areas such as

Russia (Giardia, Cryptosporidium), Nepal (Cyclospora), or

mountainous regions of North America (Giardia). In patients

with chronic bloody diarrhea and a paucity of fecal leuko-

cytes, consider amebiasis.5 As with routine stool cultures,

stool culture for ova and parasites in patients in whom

diarrhea develops three or more days after hospitalization

has an extremely low yield.49

Endoscopy/Computed Tomography

Lower gastrointestinal endoscopy should be considered in

patients with rectal bleeding, severe abdominal pain, fever,as well as negative stool tests for pathogens or otherwise

unexplained chronic diarrhea lasting longer than three

weeks.20 Biopsy and evaluation of the colonic mucosa is

crucial to exclude the presence of C. difficile

pseudomembraneous colitis, inflammatory bowel disease,

ischemic colitis, microscopic or collagenous colitis (types of

inflammatory bowel disease), and malignancy.20 In one

study, 809 HIV-negative patients with chronic non-bloody

diarrhea underwent colonoscopy. Fifteen percent of these

patients had an inflammatory cause of diarrhea, including

microscopic colitis and, to a lesser extent, Crohn’s disease

and ulcerative colitis.55

Key Points In The Management Of Patients With Diarrhea

• For most patients, diarrheal illness is short and self-limited.

• While the presence of abdominal discomfort and loose stools

can be consistent with gastroenteritis, this symptom complex

may also signal appendicitis, ischemic bowel disease,

inflammatory bowel disease, radiation enteritis, irritable bowel

syndrome, and a wide variety of other disorders.

• Correct diagnosis of an acute diarrheal illness is largely

dependent on a complete history and physical examination

rather than on extensive, costly laboratory testing.

• Treatment for many forms of diarrhea consists of

rehydration and symptomatic relief.

• Pediatric, elderly, chronically ill, or immunocompromised

patients are at greatest risk for serious etiologies and/or

complications, including dehydration.


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In patients with unexplained diarrhea and a negative

colonoscopic examination, upper gastrointestinal tract

infections (Giardia, bacterial overgrowth syndrome)

and small bowel and pancreatic diseases resulting in

malabsorption should be considered. Biopsies obtained by

upper endoscopy can determine etiologies such as celiac

sprue (which causes the malabsorption of gluten),

Whipple’s disease (a malabsorption illness caused by

Tropheryma whippelii), or other malabsorptive syndromes.

CT scanning of the abdomen and pelvis may provide

further information about small bowel and colonic disease

or extrinsic disease processes such as pancreatic tumors

that can cause diarrhea.56

Although these are not primary diagnostic consider-

ations, a working knowledge of these options is important

to facilitate the work-up of patients who present to the ED

with persistent diarrhea and a negative initial evaluation.

Treatment

Treatment decisions are influenced by several factors,

including the patient’s hydration status, the need for

symptomatic relief, and the likelihood of the presence of a

bacterial pathogen.

Rehydration

Rehydration can be accomplished by oral or intravenous

fluid administration. In patients with moderate-to-severe

dehydration, as well as those in whom vomiting disallows

adequate oral fluid intake, intravenous hydration speeds up

the recovery process. In many cases, rehydration can be

achieved with oral rehydration solutions. Fluids used for

rehydration should contain sodium, potassium, and

glucose.28 Various commercial types of oral rehydration

solutions (such as Pedialyte, Lytren, and Rehydrolyte) areavailable. Various home preparations have been proposed,

although they are not recommended in children. Addition-

ally, sports drinks, which are designed to replenish fluids

and electrolytes lost by sweating, are inadequate to replace

diarrheal sodium losses. These solutions can be effective if

they are supplemented with another source of salt such as

pretzels or crackers.16,22

The use of the “BRAT” diet (bananas, rice, applesauce,

toast) is commonly recommended, although evidence-based

data supporting its use are sparse. One evidence-based

clinical practice guideline suggests that continued use of the

patient’s preferred, usual, and age-appropriate diet should

be encouraged, and that the BRAT diet offers no advantageunless those foods are part of the usual diet.4

Symptomatic Therapy

Symptomatic therapy may be used in selected patients with

diarrhea. Patients who are afebrile and have non-bloody

diarrhea as well as most patients with chronic diarrhea

associated with inflammatory bowel disease may benefit

from the use of antimotility agents.28 Antimotility agents

should generally be avoided in patients with high fever,

sepsis, immunocompromise, bloody diarrhea, or suspected

inflammatory diarrhea because of delayed clearance of

enteric pathogens, prolonged fever, and toxic megacolon,28,53

although some argue that antimotility agents may be

used in patients with nondysenteric forms of diarrhea

caused by enteroinvasive pathogens as long as antibiotics

are also prescribed.

Agents available for diarrhea relief include loperamide,

diphenoxylate, and bismuth subsalicylate.

Loperamide is a commonly recommended antimotility

agent because of its safety and efficacy profile. It slows

intraluminal flow of liquid by inhibiting peristalsis, which

allows for increased intestinal absorption of fluid and

electrolytes, which in turn results in substantial stool

volume reduction. When used with antibiotics in patients

with traveler’s diarrhea or bacillary dysentery, loperamide

can reduce the duration of diarrhea by one day.53 It is an

opiate that does not penetrate the nervous system; thus,

there are no CNS side-effects or potential for addiction.

Diphenoxylate is less costly than loperamide; however,

it is chemically related to meperidine, can penetrate the

CNS, and may be habit-forming.

Bismuth subsalicylate helps alleviate symptoms of

dyspepsia, nausea, and diarrhea. It exerts its anti-diarrhealeffects via an antisecretory mechanism, binding of bacterial

toxins, and by its inherent antimicrobial activity. It helps

alleviate nausea and vomiting by a topical effect on the

gastric mucosa and is preferred when vomiting is a promi-

nent complaint. It has been used effectively in children with

diarrhea as well as in patients with traveler ’s diarrhea.57

Empiric Antibiotic Therapy

Authorities disagree on the indications for empiric antibiotic

therapy in diarrheal illness. When effective, antibiotics

shorten the course of an acute diarrheal illness by one

or two days. This potential benefit should be balanced

against the risk of drug-induced side-effects. The expenseof therapy and the broader societal issue of antibiotic

resistance induced by antibiotic overuse should also

be considered.5

Interestingly, although physicians often believe that

patients expect antibiotics for a variety of ailments, one

study found that patient satisfaction with medical care in

the case of diarrheal illness correlates poorly with receiving

antibiotics. An additional finding of this same study is that

physicians are not adept at identifying which patients

expect antibiotics.58

Empiric antibiotics should be considered for patients

with acute dysentery or those with moderate-to-severe

traveler’s diarrhea.5 Diarrhea lasting longer than two totwo-and-a-half days has a higher probability of having a

non-viral cause; thus, empiric antibiotics can be given in

these cases as well. Other criteria for empiric antibiotic

therapy include fever greater than 38.5˚C (101.3˚F) plus

either leukocyte-, lactoferrin-, or hemoccult-positive stools.28

Table 4 on page 13 lists the pharmaceutical regimens

recommended for patients with diarrheal illnesses. In most

instances, fluoroquinolones for adults and trimethoprim-

sulfamethoxazole (TMP-SMX) for children are reasonable

Continued on page 13


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The evidence for recommendations is graded using the following scale. For complete definitions, see back page. Class I: Definitelyrecommended. Definitive, excellent evidence provides support. Class II: Acceptable and useful. Good evidence provides support. Class III:

May be acceptable, possibly useful. Fair-to-good evidence provides support. Indeterminate: Continuing area of research.

This clinical pathway is intended to supplement, rather than substitute for, professional judgment and may be changed depending

upon a patient ’ s individual needs. Failure to comply with this pathway does not represent a breach of the standard of care.

Copyright ©2004 EB Practice, LLC. 1-800-249-5770. No part of this publication may be reproduced in any formatwithout written consent of EB Practice, LLC.

Clinical Pathway: Approach To Patients With Diarrhea

Is the patient stable?

➤ ➤

History and physical examination

(Class I)

ABCs, resuscitate, then history and

physical examination (Class I)

YES NO

Provide symptomatic therapy• Rehydration (IV or oral) (Class I)

• Antiemetics as needed (Class II)

• Antipyretics as needed (Class II)

• Antibiotics as indicated (Class II)

• Antimotility agents as indicated (Class II)

• Other symptomatic relief as needed (Class II)

➤ ➤

➤

Diagnostic evaluation as indicated

Potentially serious diagnosis

possible, or patient too ill

to discharge

Acute, self-limited process likely

➤ ➤

Patient too ill to dischargeDiagnosis clear

and stable clinical state

Consult and/or admit (Class I) Consult and/or admit (Class II) Discharge (Class I)

➤ ➤

➤ ➤ ➤


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Sample Discharge Instructions For Patients With Diarrhea

Diarrhea (loose, watery bowel movements) is often caused by an infection. Many infections that cause diarrhea

simply go away by themselves. Diarrhea can also be caused by other things, like medications, bleeding into the

stomach or bowels, diseases of the bowels, appendicitis, and many others. Diarrhea can happen by itself or may

happen with other symptoms, like cramps or pain in the stomach and bowel area, fever, vomiting, rash, or bleeding

from the rear end. You can become dehydrated (lose too much water) because of diarrhea.

Adults

Signs of dehydration

• You are very thirsty

• You feel weak or dizzy

• You faint or feel like you might faint

• Your skin is dry or very loose

• Your urine is dark

How to avoid or treat dehydration

For the first 1-2 days: Drink lots of fluids, such as

caffeine-free sodas, sports drinks, and flavoredmineral water, or an oral rehydration solution that you

can buy at the supermarket or pharmacy. Nibble on

salted crackers or pretzels (you need the salt) and

drink some orange juice or eat some bananas (for the

potassium, needed for the heart and muscles. You are

probably drinking enough if you are not thirsty and

your urine is pale yellow.

After the first 1-2 days: Try plain potatoes,

noodles, rice, boiled cereals, bread, and other similar

items. Go back to your regular diet if the diarrhea

is gone.

Do Not:

• Don’t drink milk or eat dairy products (cheese, ice

cream) for 2-3 days

• Don’t drink caffeine (tea, cola, coffee)

• Don’t drink alcohol

• Don’t drink fruit juices like prune, apple, or grape

juice (these can cause diarrhea)

Children

Signs of dehydration

• Your child is very thirsty

• Your child is very weak, sleepy, or cranky

• Your child’s skin feels cool, doughy, or loose

• Your child cries but does not make tears

• Your child does not make as much urine as usual

How to avoid or treat dehydration

Use an oral rehydration solution that you can buy

at the pharmacy or supermarket. Let your child eat a

regular diet as soon as possible. If your child is

vomiting, try having him or her drink very small

amounts of liquid until the vomiting stops.

Do Not:

• Don’t use water or sports drinks for your

dehydrated child (use an oral rehydration

solution instead)

• Don’t withhold dairy products (milk, cheese, ice

cream) from your child

• Don’t have your child drink fruit juices like prune,apple, or grape juice (these can cause diarrhea)

Medications

Use all medications exactly as your doctor advises.

You have been prescribed:

• ______________________________

• ______________________________

• ______________________________

You may also use:

• ______________________________

• ______________________________

• ______________________________

Reasons to return to the EmergencyDepartment:

• You are dehydrated

• You are vomiting and cannot eat or drink

• You have a fever over _____˚ F ( _____˚ C )

• You have blood, pus, or mucus in your diarrhea or

bowel movements

• You have pain in the stomach or bowel area

• You have bloody, black, or wine-colored diarrhea

or bowel movements

• Your sickness lasts more than _____ days

• You are not getting better at home

• You have any other problems that concern you

See your own doctor in _____ days.

Copyright ©2004 EB Practice, LLC. 1-800-249-5770. No part of this publication may be reproduced in any formatwithout written consent of EB Practice, LLC.


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Ten Pitfalls To Avoid

1. “The patient had nausea, vomiting, and diarrhea—typical

gastroenteritis, right?”

While that’s often the case, a more thorough evaluation is

required. Gastrointestinal symptoms are notoriously non-

specific. Plus, a wide variety of extra-abdominal conditions

can present with abdominal complaints (diabeticketoacidosis, thyrotoxicosis, poisonings, pneumonia).

2. “The patient had nausea, vomiting, and diarrhea. I

diagnosed ‘viral gastroenteritis’ and discharged her in

stable condition. She never told me that she recently

returned from an overseas trip!”

Travelers, patients recently discharged from the hospital,

patients with recent medication use (especially antibiotics),

and the immunocompromised are susceptible to a much

wider range of etiologies. Inquire routinely about these

aspects of their medical history. Patients often do not

realize the significance of these factors.

3. “The patient reported diarrhea. He didn’t tell me his stool

was black! How was I supposed to know that he had a

gastrointestinal bleed?”

Many patients either don’t know the characteristics of the

stool they’re passing or fail to recognize the significance of

various abnormalities (blood, mucus, melena). Ask the

patient for specifics, and if any doubt remains about what is

being passed, do a rectal examination.


gastroenteritis. How was I supposed to know it was

appendicitis?” (Part 1)

Unfortunately, there are no absolute guidelines. While

appendicitis remains a primarily clinical diagnosis,

quantifying might help. Appendicitis patients tend to have

one or two emesis episodes after their abdominal pain

begins, and they typically pass one or two loose stools.

Those with gastroenteritis, on the other hand, tend to have

multiple episodes of vomiting and voluminous loose stools.


gastroenteritis. How was I supposed to know it was

appendicitis?” (Part 2)

Serial abdominal examinations can be extremely helpful

in identifying appendicitis. Patients with gastroenteritis

generally improve with time and fluids. While the pulse

and blood pressure of patients with appendicitis may

improve with intravenous fluids, abdominal signs andsymptoms like localized tenderness, guarding, and

rebound typically persist.

6. “The patient had nausea, vomiting, and diarrhea, but was

otherwise unremarkable. I diagnosed ‘viral gastroenteritis’

and discharged her in stable condition. I had to diagnose

something, right? Too bad she got worse and had to return

to the ED a couple of days later.”

Many entities seem like viral gastroenteritis that aren’t. If

the diagnosis is unclear, stick to the facts and write

“vomiting and diarrhea with dehydration” (or something

similar) on the chart. Don’t paint yourself into a corner with

a diagnosis of viral gastroenteritis, which is often a

wastebasket category and implies premature closure of the

diagnostic thought process.

7. “In the ED, everybody with vomiting and diarrhea looks

sick at first—but if they look better after rehydration, it’susually okay to discharge them. This 65-year-old man

looked pretty good after he was rehydrated. How was I

supposed to know that he’d get worse at home? We can’t

admit everyone.”

It seems prudent to be more concerned about those

at the extremes of age (the pediatric and geriatric set),

immunocompromised individuals, and those with

severe abdominal pain. Severe abdominal pain is not

typically associated with gastroenteritis or most common

enteric pathogens.

Loose stools may also be present in patients with

ischemic bowel disease. Consider this diagnosis in the

elderly and in those with a history of vascular disease.

C. difficile-associated diarrhea is a consideration in

anyone who has been taking antibiotics during the past

three months. Certain antibiotics (e.g., clindamycin) place

the patient at particularly high risk for toxin-induced colitis.

8. “I didn’t give Mr. Jones an antimotility drug because I was

always taught it might make the patient worse. I never

expected him to become so dehydrated that he’d pass out!”

While it’s true that there are cases in which antimotility

drugs are contraindicated, they can be of significant benefit

for both comfort and for preventing dehydration in most

adults with diarrhea.

9. “When I discharged Mrs. Smith, she was stable, taking

oral fluids, and had no abdominal pain—but later she

came back in shock, severely dehydrated. What could I

have done differently?”

Written discharge instructions that the patient and her

family can understand and use are critically important. Key

reasons to return to the ED include profuse diarrhea,

dehydration (manifested by weakness, lethargy, altered

mental status, syncope/near-syncope, thirst, decreased

urine output), sustained fever, severe or persistent

abdominal pain, bloody or mucoid stools, and the inability

to take and retain oral fluids. (See also the “Sample

Discharge Instructions For Patients With Diarrhea” on page

11.) Instructions must be clear and specific.

10. “I know that diarrhea can occasionally have serious

sequelae, but it simply isn’t practical to send everyone

for follow-up!”

That’s true, but be careful. In general, otherwise healthy

patients whose symptoms resolve quickly do not require

follow-up. But certain subsets of patients—such as those

with chronic symptoms, the elderly, the very young, the

immunocompromised, and those with co-morbid

illnesses—should be referred for follow-up. And, as

mentioned in the prior item, discharge instructions should

be very clear about circumstances under which patients

should seek further medical care.


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choices.5 Empiric therapy with metronidazole (or other

anti-Giardia agent) can also be considered in patients

with diarrhea lasting 2-4 weeks, without systemic symp-

toms or dysentery.16

In suspected cases of C. difficile-associated diarrhea,

the offending antibiotic should be stopped if possible

and treatment with oral metronidazole begun. Metronida-

zole should be stopped if the assay for C. difficile toxin

is negative.14

When empiric antibiotic therapy is not employed

judiciously, it can be ineffective or even harmful. If vomiting

is a prominent symptom of the illness, a viral source is more

likely. Antibiotics should also not be used if the diarrhea is

thought to be due to Shiga toxin-producing E. coli. This

decision will involve physician judgment since no diagnos-

tic test will yield an immediate result to help the clinician.

Keep in mind that Shiga toxin-producing E. coli (E. coli

0157:H7 being the most common type) causes bloody

diarrhea. E. coli 0157:H7 outbreaks have been associated

with undercooked ground beef as well as with fresh

produce such as unpasteurized apple cider, cabbage, and

alfalfa sprouts.2

Traveler’s Diarrhea

Antibiotics commonly used in the treatment of traveler’s

diarrhea include quinolones, TMP-SMX, as well as nonab-

sorbable or poorly absorbed antibiotics such as rifaximin

and aztreonam.59,60 A comparison of two different doses of

TMP-SMX with or without loperamide vs. loperamide alone

in American adults with acute diarrhea in Mexico revealed

that combination therapy with TMP-SMX and loperamide

was the most efficacious regimen.61

Several studies have also provided data regarding the

efficacy and safety of rifaximin for the treatment of

traveler’s diarrhea. Adults with acute traveler’s diarrhea

who took rifaximin vs. placebo for three days had earlier

resolution of symptoms (average, slightly more than one

day).62 A randomized, controlled trial comparing rifaximin

with TMP-SMX revealed an 11% clinical failure rate with

rifaximin vs. a 29% clinical failure rate with TMP-SMX.63 In

another comparison of rifaximin with ciprofloxacin, no

significant differences were noted between the two treat-

ment groups.59

There is an increasing emergence of fluoroquinolone-

resistant Campylobacter, with the rate of resistance exceeding

80% in Southern Asia.53 For patients with travel histories

to this part of the world, erythromycin or azithromycinare alternatives.53

Prevention Of Traveler’s Diarrhea

Advising patients on ways to minimize the risk of traveler ’s

diarrhea for future trips may be helpful, as well. Beverages

should be carbonated or steaming hot. Uncarbonated

water, bottled water, and even ice may be unsafe. Dry

foods (bread), acidic foods (citrus), and foods with high

sugar content (jellies, syrups) are safe. Buffet items and

green, leafy vegetables (which are washed in water)

should be avoided.57

Advise travelers to take along loperamide or bismuth

subsalicylate as well as an antibiotic. (However, note thatsulfa-based medications can produce photosensitivity.)

One randomized, controlled comparison of bismuth

subsalicylate with loperamide showed similar efficacy;

however, the loperamide group passed fewer stools than

the bismuth subsalicylate group.64 On the other hand,

bismuth subsalicylate has the additional advantage of

alleviating nausea and vomiting and has been shown to

prevent traveler’s diarrhea. In a randomized, double-blind,

placebo-controlled trial, diarrhea developed in 23% of

students receiving bismuth subsalicylate compared with

61% of students taking a placebo. The treatment group

experienced fewer intestinal complaints and were less likely

to pass loose or watery stools. In subjects in whom diarrheadid occur, enteropathogens were identified less commonly

in the treatment group (33%) compared to the placebo

group (71%).57

Special Circumstances

Immunocompromized Patients

Patients with HIV/AIDS are especially prone to diarrheal

illnesses. About half of North American AIDS patients will

develop diarrhea at some point in their illness. The inci-

dence of diarrhea in AIDS patients throughout the develop-

Continued from page 9

Table 4. Empiric Antibiotic TherapyRegimens For Suspected InfectiousDiarrhea.

1. Temperature greater than 38.5˚C (101.3˚F) and oneof the following:

• Guaiac-positive stools or presence of fecal leukocytes or

fecal lactoferrin• Also, consider empiric antibiotics in patients with

diarrhea lasting longer than 48 hours

Treatment:• A fluoroquinolone in adults

• Trimethoprim-sulfamethoxazole in children

Treatment period: 1-5 days

2. Moderate-to-severe traveler’s diarrheaTreatment:

• A fluoroquinolone in adults

• Trimethoprim-sulfamethoxazole in children

Treatment period: 1-5 days

3. Diarrhea for 2-4 weeks without systemic symptomsor dysentery

Treatment:• Consider a seven- to 10-day course of metronidazole or

other anti-Giardia agent

4. Nosocomial diarrheaTreatment:

• Stop the suspected offending antibiotic

• Metronidazole (first line) or vancomycin (in case of

metronidazole failure or when metronidazole is

contraindicated or not tolerated)

Treatment period: 10 days if assay for C. difficile is positive.

Stop antibiotic if assay for C. difficile is negative.


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ing world approaches 100%.65

While HIV/AIDS patients are at risk for all of the

diarrheal ailments that afflict the immunocompetent

population, they can develop enteric infections from a

variety of unusual viral, parasitic, protozoal, and bacterial

organisms. Malignancies affecting the gastrointestinal tract,

such as lymphoma and Kaposi’s sarcoma, may produce

diarrhea, as can many antiretroviral medications.65,66 Finally,

many AIDS patients receive multiple or sustained courses of

antibiotics, predisposing them to C. difficile-associated

diarrhea.66 Therefore, it is important to maintain a broad

differential diagnosis, consider a more aggressive diagnostic

strategy, involve consultants early when appropriate, and

consider hospitalization to improve diagnostic certainty

through a combination of testing, observation, and consult-

ant involvement. (See also the January 2002 issue of

Emergency Medicine Practice, “HIV-Related Illnesses: The

Challenge Of ED Management.”)

Because certain symptoms may suggest particular

organisms (see Table 5), the approach to the HIV/AIDS

patient with diarrhea begins with the history. Definitive

diagnosis, however, is likely to result from either microbio-logical studies or endoscopy.65,66 Begin by assessing the

patient’s immune status. Ask about specific exposures

(sexual practices, travel history, and medications including

recent antibiotics). Inquire also about the stool characteris-

tics (bloody, mucoid, watery) and all associated symptoms

(e.g., fever, vomiting, abdominal pain or cramping, tenes-

mus, bloating, weight loss).65,66 What may seem like an acute

bout of diarrhea may actually represent the beginning of

chronic symptoms. Routine laboratory tests should be

ordered based on the clinical situation.65 Many authorities

recommend that in AIDS patients, a stool culture should be

done, along with C. difficile toxin and ova and parasite

testing.66 If these studies are negative, referral to a gastroen-terologist for endoscopic investigations could be the next

step in the patient’s evaluation.65,66 In the AIDS patient with

chronic diarrhea and a negative microbiological work-up for

infectious agents, authorities are divided on the best

approach. Some advocate symptomatic care, some a course

of empiric antibiotics, and still others suggest endoscopy

with gastrointestinal mucosal biopsy; symptoms and

disease stage guide these decisions.17 Endoscopy often

produces a definitive diagnosis in AIDS patients with

chronic diarrhea and negative stool studies.67

ED treatment options include rehydration, antimotility

agents, and empiric antibiotics, as discussed earlier in this

article. Consultation or referral to the patient’s primary care

provider or infectious disease specialist regarding antibiotic

therapy or changes in antiretroviral therapy are advisable.

Elderly Patients

Diarrheal illnesses are important causes of death and

disability in the elderly. Not only are more serious etiologies

more common in the elderly, the physiological stresses of

diarrheal illness are more challenging for this population.

Age-related declines in immune system functioning,

physiologic changes of aging, medications (e.g., those that

inhibit gastric acid secretion, antibiotics, vasoconstrictors,

and others), and environmental factors (e.g., group living in

nursing homes) all contribute to the elderly patient’s

susceptibility to develop diarrhea.68

Furthermore, elderly patients with diarrhea are often

profoundly dehydrated due to fluid losses associated withtheir illness, fever, an age-related disordered thirst mecha-

nism, co-existing illnesses (e.g., diabetes mellitus), medica-

tions (e.g., diuretics) and limited access to fluids due to

infirmity. Prompt, adequate rehydration is essential;

however, intravenous rehydration of the elderly individual

may be complicated by the presence of cardiovascular

disease or renal dysfunction, thus limiting rapid, large-

volume fluid administration.68

Ischemic colitis, diverticulitis, bacterial overgrowth,

and colonic malignancies are all more common in the

elderly and may present with loose stool.7,68,69 Infections—

notably, C. difficile, E. coli 0157:H7 and Salmonella species—

are more common in the elderly.68,70 Infectious diarrhea inthe elderly is associated with a higher mortality rate.68

If medications are indicated for an elderly patient with

diarrhea, be aware of drug interactions and side-effects,

particularly if the patient is already on multiple medica-

tions. Antacids may reduce the potency of fluoroquinolones.

Additionally, fluoroquinolones can increase theophylline

and warfarin levels and can either increase or decrease

phenytoin levels. Metronidazole can cause nausea and

vomiting, exacerbating the situation for a patient who

initially presented with a gastrointestinal complaint.

Drinking alcohol while taking metronidazole must be

strictly avoided since a disulfiram-like reaction can ensue.

Also, warfarin, phenytoin, and phenobarbital metabolismmay all increase in the patient on metronidazole, potentiat-

ing their effect.68

Be particularly cautious when evaluating elderly

patients with diarrhea combined with abdominal pain.

Elderly patients with abdominal pain tend to have more

serious, often surgical, illnesses that present atypically

or go unrecognized longer.69 (See also the premier issue

of Emergency Medicine Practice, “Assessing Abdominal

Pain In Adults: A Rational, Cost-Effective, And Evidence-

Based Strategy.”) Specific surgical diagnoses to consider

Table 5. Diarrheal Syndromes In PatientsWith HIV/AIDS.

Abdominal cramps, bloating, nauseaPossible agents: Cryptosporidia, microsporidia, isospora,

giardia, cyclospora, and Mycobacterium avium complex

Profuse watery diarrhea, weight loss, electrolytedisturbance (especially in advanced disease)

Possible agent: Cryptosporidia

Bloody stools, fever, abdominal crampsPossible agents: Invasive bacteria, C. difficile,

cytomegalovirus

Adapted from: Sax PE. Opportunistic infections in HIV disease: downbut not out. Infect Dis Clin North Am 2001;15(2):433-55.


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in the elderly patient with diarrhea include bowel

obstruction, appendicitis, mesenteric ischemia, neoplasm,

and diverticulitis.69

Pediatric Patients

Diarrhea is very common in children, especially among

those who attend day care. While most children in devel-

oped nations have mild, self-limited disease, pediatric

patients are susceptible to more adverse outcomes—

especially dehydration—than their healthy adult counter-

parts.21 In the United States, about 9% of all hospitalizations

of children younger than 5 years are because of diarrhea.71

While pediatric patients are susceptible to more

adverse outcomes from diarrheal illnesses, the approach is

generally the same. As with adults, infectious causes

predominate, although children have more of a predisposi-

tion to rotavirus. Another common non-infectious cause in

children is the excessive consumption of sugary, clear

liquids, which can cause copious, watery stools. The wary

practitioner should also keep more serious diagnoses such

as intussusception and Meckel’s diverticulum in mind.

In most cases, prevention of dehydration is the primaryconsideration. Oral rehydration methods are preferred.

After rehydration, recommend prompt resumption of a

regular diet, supplemented with oral rehydration solution

as tolerated. In vomiting children, frequent, small-volume

oral intake is recommended.4

In children, as a general rule, pharmacologic agents

should not be used to treat acute diarrhea.21 While some

well-designed studies have shown statistically significant

results for certain agents, the results were not clinically

significant, and published evidence-based guidelines do not

support their use in children.4,21 Antibiotic use may be

considered in patients in high-risk categories or with serious

bacterial infections.4

Hemolytic uremic syndrome is a complication of E. coli

0157:H7 infection that occurs primarily in children. While

rare, it is the most common cause of acute kidney failure in

infants and children. Early symptoms include vomiting and

diarrhea (sometimes bloody), fever, and irritability or

lethargy. Later, urine output, decreased consciousness,

pallor, bruising, petechiae, or jaundice may occur. An

enlarged liver or spleen may be present. Laboratory studies

will show evidence of hemolytic anemia and acute renal

failure. Administration of packed red blood cells may be

necessary, and severe cases may require dialysis. Neverthe-less, most children receiving treatment recover completely

with no long-term consequences.

Cost- And Time-Effective Strategies For Patients With Diarrhea

1. Consider minimizing testing in those with acute

gastroenteritis by obtaining an adequate history and

performing a sufficient physical examination.

Routine laboratory testing is unhelpful for most patients with

acute diarrheal illnesses. The white blood cell count is neither

sensitive nor specific for any particular illness characterized

by diarrhea. The white blood cell differential is often similarly

unhelpful. Hemoglobin and hematocrit levels may be useful

in those patients with blood loss, but otherwise are of limited

to no value. Electrolytes are rarely disordered significantly in

young patients with short periods of diarrhea. Renal function

tests are a poor screen for dehydration. Urine-specific gravity

may be somewhat more helpful, but easily observable clinical

features like skin perfusion, vital signs, urine output, and

thirst may be best of all.

Caveat: The WBC count can be helpful in identifying C.

difficile (which may require admission) or enteric fever. In

addition, eosinophilia may indicate alternative diagnoses.

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