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SPEAKER: Dr ASHOK KUMAR

CHAIRPERSON: Dr ARDAMAN SINGH

DIARRHEA: is defined as passage of abnormally liquid or unformed stool at an increased frequency. For adult on typical western diet, stool wt>200g/d can be considered diarrhea.

PSEUDODIARRHEA: frequent passage of small vol. of stool,is often asso. With rectal urgency and a/c IBS or proctitis.

FECAL INCONTINENCE: is involuntary passage of rectal contents and is most often caused by neuromuscular disorders or structural anorectal problems

Pseudodiarrhea and fecal incontinence occur at prevalence rate comparable to or higher than that of chr. Diarrhea and should always be considered in pt. complaining of diarrhea.

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Acute diarrhea: <2 wk

Chronic diarrhea: >4 wk

Persistent diarrhea :2-4 wk

4 weeks– cut off point3

SECRETORY CAUSES Exogenous stimulant laxative Chronic ethanol ingestion Endogenous laxatives(dihydroxy

bile acids) Bactrial inf. Bowel resection,disease ,fistula Partial bowel obst.,fecal impaction Harmone producing

tumors(carcinoid,VIPoma,medullary ca) thyroid,mastocytosis,gastrinoma,colorectal villus adenoma)

Addison’s disease Congenital electrolyte abs. defect idiopathic

OSMOTIC CAUSES Osmotic laxative(MG+

+,PO4,SO4--) Lactase and other disaccharide

defeciency Nonabs. CHO (sorbitol,lactulose

polyethylene glycol)INFLAMMATORY CAUSES Idiopathic inflm,bowel

disease(CD,UC) Lymphocytic and collagenous

colitis Immune-related mucosal

disease(1,2nd immunodeficiences,food allergy,eosinophilic gastroenteritis,GVHD) Infections(invasive bacteria,viruses,and parasites,Brainerd diarrhea)

Radiation injury Gastrointestinal malignancies

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STEATORRHEAL CAUSES Intraluminal

maldigestion(pancreatic exocrine deficiency,bactrial overgrowth,bariatric sx,liver dis.)

Mucosal malabsorbtion(celiac sprue,whipple’s disease,inf, abetalipoproteinemia , ischemia)

Post mucosal obst (1, 2nd lympathic obst.)

FACTITIAL CAUSES Munchausen Eating disorders

DYSMOTILE CAUSES

Irritable bowel syndrome(including post-infectious IBS) Visceral neuromyopathies

Hyperthyroidism

Drugs(prokinetic agents) Postvagotomy

IATROGENIC CAUSES Cholecystectomy Ileal resection Bariatric surgery Vagotomy,fundoplication

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Antibiotics Antiretroviral agents Antineoplastic agents Anti-inflammatory agents (NSAIDs, gold, 5-ASA) Antiarrhythmics (quinidine) Antihypertensives (β blockers) Oral hypoglycemics (metformin, acarbose) Antacids (magnesium-containing) Acid-reducing agents (H2 blockers, PPIs) Colchicine Prostaglandin analogs (misoprostol) Theophylline Vitamin and mineral supplements Herbal products Heavy metals

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Due to derangement in fluid and electrolyte transport across the enterocolonic mucosa.

CLUE:Watery,Large volume ( >1 L/d),painless, little change with fasting; normal stool osmotic gap

1.Medications2. Bowel resection,mucosal

disease,enterocolic fistula).3. Hormonally mediated (uncommon)4.Congen.defect in ion absorption:

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When ingested,poorly absorbable,osmotically active solute draw enough fluid into lumen to exceed the reabsorptive capacity of the colon.

CLUES: Stool volume decreases with fasting; increased stool osmotic gap(>50mosmol/l).

1 magnesium (antacids, laxatives)2. Medications3 Disaccharidase deficiency

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As stool leaves the colon, fecal osmolality is equal to the serum osmolality, ie, approximately 290 mosm/kg. Under normal circumstances, the major osmoles are Na+, K+, Cl–, and HCO3–. The stool osmolality may be estimated by multiplying the stool (Na+ + K+) × 2 (multiplied by 2 to account for the anions)

The osmotic gap is the difference between the measured osmolality of the stool (or serum) and the estimated stool osmolality and is normally less than 50 mosm/kg

An increased osmotic gap implies that the diarrhea is caused by ingestion or malabsorption of an osmotically active substance

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>7g/d fat in stool(Small intestine disease15-25g/d,pancriatic exocrine def.>32g/d).

CLUE:greasy ,Foul smelling,difficult to flush,as/o with wt. loss ,nutritional def.(amino a,vitamins).

Intraluminal maldigestion Mucosal malabsorption Postmucosal lymphatic obstruction

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CLUE:Fever, hematochezia, abdominal pain

Mechanism depending on lesion site(fat malabsorption,fluid/electrolyte,hypermotility from cytokinins)

1.Inflammatory bowel disease2. Microscopic colitis3.Immunodeficiency4.Eosinophillic gastroenteritis 11

Parasites: Giardia lamblia, Entamoeba histolytica, Cyclospora

AIDS-related: Viral: Cytomegalovirus, HIV infection

Bacterial: Clostridium difficile, Mycobacterium avium complex

Protozoal: Microsporida, Cryptosporidium, Isospora belli

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Abnormal intestinal motility secondary to systemic disorders or surgery may result in diarrhea due to rapid transit or to stasis of intestinal contents with bacterial overgrowth resulting in malabsorption

Stool feature suggestive of secretory diarrhea,mild steatorrhea may be there.

Hyperthyroidism, diabetic diarrhea ,carcinoid syndrome.

medications(PGs ,prokinetic drugs). Irritable bowel syndrome.

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Approximately 15% of patients with chronic diarrhea have factitial diarrhea caused by surreptitious laxative abuse or factitious dilution of stool.

Munchausen syndrome(self inj. For secondary gain,women),eating disorder.

Hypotension,hypokalamia. Psy. conselling beneficial. 14

OsmoticSecretory

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Onset Congenital Abrupt Gradual Travel history

Exposure to contaminated water

Weight loss

Dietary history

Chloridorrhea Infections, idiopathic secretory

diarrhea All other etiologies Infectious diarrhea Aeromonas, Plesiomonas Giardiasis, Cryptosporidiosis Brainerd diarrhea Malabsorption, pancreatic exocrine

insufficiency, neoplasm “Sugar-free” foods with sorbitol,

mannitol , lactase deficiency, fructose intolerance

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Previous treatments

Systemic illness

Abdominal pain

Excessive flatus/bloating

IV drug use, sexual promiscuity

Secondary gain/Fixation on body image

Institutionalized patients

Medications, radiation enteropathy, surgery (bowel, gallbladder), pseudomembranous colitis

Hyperthyroidism, IBD, diabetes

Mesenteric vascular insufficiency, IBD, IBS

Carbohydrate malabsorption, small bowel bacterial overgrowth

HIV infection

Laxative abuse

Medication, C. difficile colitis, tube feeding, ischemia, fecal impaction with overflow diarrhea

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Epidemiological and historical features Implication

Young patients Inflammatory Bowel Disease Tuberculosis Functional bowel disorder (Irritable bowel)

Older patients Colon Cancer Diverticulitis

DiarrheaDiarrhea alternates with alternates with ConstipationConstipation

Colon Cancer Laxative abuse Diverticulitis Functional bowel disorder (Irritable bowel)

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No relationship to time of day: Infectious Diarrhea Morning Diarrhea and after meals

Gastric cause Functional bowel disorder (e.g. irritable bowel) Inflammatory Bowel Disease

Nocturnal Diarrhea (always organic) Diabetic Neuropathy Inflammatory Bowel Disease

Intermittent DiarrheaDiverticulitisFunctional bowel disorder (Irritable bowel) Malabsorption

Persistent Diarrhea Inflammatory Bowel DiseaseLaxative abuse

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Despite normal appetite HyperthyroidismMalabsorption

Associated with fever Inflammatory Bowel Disease

Weight loss prior to Diarrhea onset Pancreatic Cancer TuberculosisDiabetes MellitusHyperthyroidism TRAVEL

Traveler’s diarrhea

Infectious diarrhea21

Water: Chronic Watery Diarrhea Blood, pus or mucus: Chronic Inflammatory Diarrhea

Foul, bulky, greasy stools: Chronic Fatty Diarrhea

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SMALL BOWEL DIARRHEASMALL BOWEL DIARRHEA LARGE BOWEL DIARRHEALARGE BOWEL DIARRHEA

Large stool volumeLarge stool volume Small amount of stoolSmall amount of stool

Increased frequency with Increased frequency with large volume stoollarge volume stool

Increased frequency with Increased frequency with small volume stoolsmall volume stool

No urgency No urgency urgencyurgency

No tenesmusNo tenesmus Tenesmus presentTenesmus present

No mucusNo mucus Mucus in stoolMucus in stool

No bloodNo blood Blood may be presentBlood may be present

Central abdominal pain Central abdominal pain Pain in left iliac fossa Pain in left iliac fossa relived by defecationrelived by defecation

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drug induced diarrhea

Food borne illness

waterborne illness

High fructose corn syrup

Excessive sorbitol or mannitol

Excessive coffee or other caffeine 24

Childhood diarrhea-resolves-re-emergence in adulthood– celiac disease

Uncontrolled diabetes

Pelvic radiotherapyPAST SURGICAL HISTORY Jejunoileal bypass

Gastrectomy with vagotomy

Bowel resection

Cholecystectomy25

Painless diarrhea Recent onset in an older patient Nocturnal diarrhea (especially if wakes

patient) Weight loss Blood in stool Large stool volumes: >400 grams stool

per day Anemia Hypoalbuminemia increased ESR

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Celiac sprue (dermatitis herpetiformis) Mastocytosis (urticaria pigmentosa) Amyloidosis (macroglossia, purpura) Addison’s disease (hyperpigmentation) Glucagonoma (migratory necrolytic

erythema) Carcinoid syndrome (flushing) Degos’ disease (malignant atrophic

papulosis) IBD (erythema

nodosum,pyoderma gangrenosum)

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Peripheral neuropathy, orthostatic hypotension

Thyroid nodule

Right-sided cardiac murmur, hepatomegaly

Arthritis

Lymphadenopathy Peripheral vascular

disease/abdominal bruits

Amyloidosis

Medullary carcinoma of the thyroid

Carcinoid syndrome

IBD, Whipple’s, infections

AIDS, lymphoma Mesenteric vascular

insufficiency

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General appearance and mental status

Vital signs

Body weight

Exophthalmos (hyperthyroidism)

Aphthous ulcers (IBD and celiac disease)

Lymphadenopathy (malignancy, infection or Whipple's disease)

Enlarged or tender thyroid (thyroiditis, medullary carcinoma of thyroid)

Clubbing (liver disease, IBD, laxative abuse, malignancy)30

Surgical scars

abdominal tenderness

Masses

Hepatosplenomegaly

Borborygmus on auscultation malabsorption bacterial overgrowth obstruction, or rapid

intestinal transit.31

Signs of incontinence – skin changes from chronic irritation, gaping anus, weak sphincter tone.

Crohn's disease perianal skin tags Ulcers fissures abscesses Fistulas stenoses.

Fecal impaction or masses might be noted. SYSTEMIC EXAMINATION wheezing and right-sided heart murmurs,episodic flushing,dyspnea

(carcinoid syndrome)

Arthritis,uveitis,polyarthralgia,cholestatic,liver disease(IBD, Whipple's disease)

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24-hour stool collection for weight and quantitative fecal fat–A stool wt. of > 300 g/24 h confirms the presence of diarrhea, justifying further workup. A wt. >1000–1500 g suggests a secretory process. A fecal fat > 10 g/24 h indicates a malabsorptive process

Categorize diarrhea into watery, inflammatory, fatty Timed collection is best, spot tests on random stool

sample more practical- Occult blood- White blood cells - pH- Sudan stain for fat- Cultures- Laxative screen- Electrolytes, osmolality

-Stool for ova and parasites34

Occult blood and white blood cells:- Primarily define inflammatory diarrhea- Wright stain: Sensitivity 70%, specificity 50% for leukocytes- Fecal calprotectin and lactoferrin less operator dependent

pH:- Low pH (< 6) generally indicative of carbohydrate malabsorption

Sudan stain:- Fatty diarrhea (steatorrhea) - Gold standard: Quantitative estimation of stool fat on collected specimen - Qualitative estimation feasible on random sample, - Semiquantitative methods (number and size of fat globules) correlate well with quantitative collection

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Stool cultures:- Infection: Usually inflammatory diarrhea- Bacterial infection rarely cause of chronic diarrhea in immunocompetent host - Routine cultures are low yield - Special techniques for Aeromonas and Plesiomonas- Ova and Parasites- Always consider giardiasis (stool ELISA for Giardia antigen)

Laxative screen:- High index of suspicion- Stool for bisacodyl and phenolphtalein, urine for anthraquinones- Confirm on another sample before confronting patient

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Stool electrolytes:Stool osmotic gap: 290 – 2([Na+] + [K+]) - Gap < 50 mOsm/Kg: Pure secretory diarrhea- Gap > 125 mOsm/Kg: Pure osmotic diarrhea- Gap 50-125 mOsm/kg: Mixed or mild carbohydrate malabsorption

Measured stool osmolality:- Not used to calculate gap- Useful in cases of unexplained diarrhea- Low measured stool osmolality (< 290 mOsm/Kg) suggestive of contamination with water or dilute urine

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Fecal fat (abnormal if >10 grams/24 hours)

Stool ova and parasites (2-3 samples)

Giardia lamblia antigen Indicated for diarrhea >7 days and >10 stools/day

Clostridium difficle toxin Indicated if recent antibiotics or hospitalization

Consider testing stools for laxative abuse

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39Fig. 22.21 The “face” of a Giardia lamblia trophozoite.

Routine laboratory tests–CBC, serum electrolytes, liver function tests, ca++, phosphorus, albumin, TSH, total T4, and prothrombin time should be obtained.

Anemia occurs in malabsorption syndromes (vitamin B12, folate, iron) and inflammatory conditions.

Hypoalbuminemia is present in malabsorption, protein-losing enteropathies, and inflammatory diseases.

Hyponatremia and non–anion gap metabolic acidosis may occur in profound secretory diarrheas. Malabsorption of fat-soluble vitamins may result in an abnormal prothrombin time, low serum calcium, low carotene, or abnormal serum alkaline phosphatase 40

In patients with suspected secretory diarrhea

serum VIP (VIPoma)

gastrin (Zollinger-Ellison syndrome)

calcitonin (medullary thyroid carcinoma)

cortisol (Addison's disease)

urinary 5-HIAA (carcinoid syndrome)

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Calcification on a plain abdominal radiograph confirms the diagnosis of chronic pancreatitis.

An upper gastrointestinal series or enteroclysis study is helpful in evaluating Crohn's disease, lymphoma, or carcinoid syndrome.

Colonoscopy is helpful in evaluating colonic inflammation due to IBD.

Upper endoscopy malabsorption due to mucosal diseases. with a duodenal aspirate and small bowel biopsy is also useful in patients with AIDS and to document Cryptosporidium, Microsporida, and M avium-intracellulare infection.

Abdominal CT is helpful to detect chronic pancreatitis or pancreatic endocrine tumors.

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Chronic diarrhea

Blood PR

Features,stool,

Suggest malabsorptio

nPain aggravated

before BM,relieved

withBM ,sense incomplete evacuation

No blood features of malabsorp

tion

Colonoscopy +Biopsy Small

bowel:imaging,biopsy,aspirate

Suspect IBS

ConsiderFunctional diarrhea

Dietary exclusion

eg.Lactose sorbitol

Limited screen for organic

disease43

Low Hb,Alb,abnormal MCV,MCH; excess fat in stool

Opioid Rx + follow up

Persistent chronic diarrhea

Titrate Rx to speed of

transit

Colonoscopy + Biopsy

Small bowel:X

ray,biopsy,aspirate;stool

48-h fat

Stool vol,OSM,PH;Laxative screen;Hor

monal screen

Stool fat >20g/d

Pancreatic function

Normal and stool fat <14g/d Full gut

transit

Chronic diarrhea

Screening test all normal

Low k+

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Treatment depend upon specific etiology Curative ,suppressive or empirical.

CURATIVE:recetion of colorectal ca.,antibiotic for whipple dis.,drug discontinuation of a drug.

SUPPRESSIVE:(supress the underlying mechanism) Lactose avoid in lactase def. Gluten diet for celiac sprue. Glucocorticoids and anti inflammatory for IBD PPI for gastrinoma Cholestyramine for ileal bile acid malabsorbtion Octreotide for malignent carcinoid syndrome Prostaglandin (-) indomethacin:medullary ca thyroid Pancreatic replacement:pancreatic insufficiency

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EMPERICAL:mild to mod. Watery diarrhea(diphenoxylate,loperamide),severe(codeine,opium)

Avoid in IBD as toxic megacolon ppt.

Clonidine:diabetic diarrhea

Fluid and electrolyte Fat soluble vitamin

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Drug Class Agent DoseOpiates Diphenoxylate

LoperamideCodeineMorphineTincture of opium

2.5-5 mg QID2-4 mg QID15-60 mg QID2-20 mg QID2-20 drops QID

Adrenergic agonist Clonidine 0.1-0.3 mg TID

Somatostatin analog Octreotide 50-250 µg SQ TID

Bile acid-binding resin Cholestyramine 4 g once daily to QID

Fiber supplements PsylliumCalcium polycarbophil

10-20 g daily5-10 g daily

Others ProbioticsHerbals (berberine, arrowroot) 48

THANKS..

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