26 March 1977 MEDICAL JOUR AL 409

The Aetiology, Diagnosis and Treatment of Constipationand Diarrhoea in Geriatric Patients

S. BANK, 1.

SUMMARYConstipation and, to a lesser extent, diarrhoea, are notuncommon in the elderly and are frequently due to non­organic causes. Despite this, disturbances in bowel habitalways warrant the consideration of possible organiccauses. Carcinoma of the colon and endocrine causes arefrequently overlooked and rectal examination is mandatoryin all patients to exclude rectal carcinoma and faecalimpaction. Rectal bleeding, of course, is as alarming asymptom in the elderly as it is in younger people.

S. Afr. med. J., 51, 409 (1977).

It is often assumed that changes in bowel habit in theelderly are part of the ageing process. These patients arefrequently labelled as having 'lazy bowels', 'lax sphinc­ters', 'loss of muscle tone' or a 'touch of piles', withoutconsideration of a possible organic cause. Functional boweldisorders occur in all age groups and tend to increasewith age in those who suffer the stress of loneliness,bereavement and financial insecurity. Others may u etheir bowels to 'capture' the attention of unsympatheticrelatives.

This article stresses the fact that constipation and diar­rhoea are common symptoms in the geriatric age group,and that due consideration must be given to the remediableorganic causes of bowel disease. The effects of consti­pation and diarrhoea are frequently more drastic physicallyand psychologically at this age; and within reason, theinvestigative profile should not alter on the grounds ofage alone.

The dominant consideration in any patient over the ageof 40 who presents with recent constipation or diarrhoea,or any change in bowel habit, is the differentiation between'simple' constipation or 'functional' diarrhoea on the onehand, and carcinoma of the colon and rectum on theother. There are unfortunately too many instances of de­lay in the diagnosis of colorectal cancer because of failureto carry out rectal examination, or tests for occuJt blood,and haemoglobin and ESR estimations, or because of thereluctance to subject older patients to the inconvenienceand expense of sigmoidoscopic and barium enema exam­ination. It is only after colorectal cancer has been excludedthat a more relaxed approach to the problem can be under­taken. Why this preoccupation with colorectal cancer?Firstly, it is one of the few gastro-intestinal cancers with

Gastro-intestinal Clinic, Department of Medicine GrooteSehuur Hospital and University of Cape Town '

S. BANK, "'LB. CH.B., F'.R.C.P., Associate Professor and ChiefSpecial'ist

I. N. MARKS, B.SC., M.B. CH.B., F.R.C.P., Senior Lecturerand Senior Specialist

Dale received: 25 October 1976.

7

. MARKS

a reasonably good prognosi after treatment, and a 5­year cure rate of ome 50% may be expected in earlyle~lOns. Secondly, the quality of the life of a patientWIth unresected lesions is 0 appalling that palliativesurgery or radiotherapy is often till indicated whenthere are more extensive lesions, and occa ionally evenIn the presence of metastase .

APPROACH TO CONSTIPATIO ANDDIARRHOEA

Constipation

Co~stipation is such a common symptom in the elderlythat It may be asked whether very elderly constipatedpatIent should be subjected to special investigation. Theanswer to this question is not simple, and depends to alarge extent on a careful assessment of the history, physicalexamination and the findings of routine investigationscomprising rectal examination, measurement of haemoglo­bm and ESR and tests for occult blood in the tools.Patients with long-standing constipation, who have hadrecent depressive illness, a change in diet, or debility dueto disease, or those who are taking constipating medi­cines, could initially be treated symptomaticaUy and thenbe reassessed after a period of a few weeks. However,patients with constipation of recent onset, sudden aggra­vation of existing constipation with recent abdominal pain,or the passage of blood and mucus in the tools shouldalways be subjected to sigmoidoscopy and barium enemaexamination.

Diarrhoea

Clearly, the approach to diarrhoea will depend on theacuteness of onset, the response to early treatment, anassessment of the possible aetiology and a considerationof the expense of further investigations. The history andphysical examination often provide a lead as to the area ofgut involved. Early morning rushes, hypogastric cramp ,tenesmus and the passage of blood are fairly specific in­dications that the problem originates in the colon. Steator­rhoea or greenish-yellow stools suggest a mall-bowelor pancreatic lesion. Most problems tend to arise whenthe character of the stool is non-specific, and is eitherwatery or pultaceous, since both the upper and lowerbowel may require investigation.

By and large, mo t patient with diarrhoea of acute onsetwill be given the pos ible benefit of antibiotic therapy.This temporary 'blind' approach is not unreasonable in theelderly, provided that attention is paid to rehydration,electrolyte losses and the addition of con tipating agents.The very ill patient with pyrexia is probably be t managedin ho pitaJ. If the diarrhoea doe not ub ide within a

410 SA MEDIESE TYDSKRIF 26 Maart 1977

few days, 3 stool cultures should be done. Treatment withantibiotics or repeated changes in antibiotics should onlybe persisted with if there are definite indications, e.g.positive culture.

Eventually it will have to be decided whether furtherinvestigations are required, particularly if physical exam­ination fail to reveal an overt physical or psychosomaticcause. Minimal basic investigations would then be stoolcultures; determination of haemoglobin concentration andsedimentation rate; rectal and sigmoidoscopic examination;tests for occult blood and a barium meal and follow­through and/ or barium enema, depending on which areaof the gut is suspected of being involved.

The Problem of the Barium Enema

A barium enema is an unpleasant and uncomfortableprocedure, particularly for the elderly. Patients shouldtherefore be assessed as to the extent of bowel preparationrequired and a purgative should be given after the pro­cedure to reduce the risk of barium impaction. Althoughadequate preparation of the bowel is essential, we believethat this can be achieved without subjecting the patientto bowel washouts. Good preparation may be achievedif only clear fluids are taken for 48 hours before the proce­dure, if the patient's usual dose of purgative, or 2·4tablets of sennosides A and B (Senokot; Reckitt and Col­man) are taken 2 nights before the enema, or if, on thenight before the enema, a solution of magnesium citrate(Martindale) in a dose of 200 - 250 ml is given. If theconstipation is severe and the patispt able-bodied, 4bisacodyl (Dulcolax; Boehringer Ingelheim) or 4 tablets ofsennosides A and B may be given as well. The rather dis­turbing bowel washout may sometimes be added to thisregimen, should the referring doctor consider it necessary.

Over-enthusiastic bowel preparation is even leis justifiedin the elderly with diarrhoea, and it may be harmful toinstitute a full regimen of purgation and washout in patientsin whom inflammation of the large bowel, e.g. ulcerativecolitis, is suspected as a cause of diarrhoea. A 24-hourliquid diet and a dose of magnesium trisilicate or mag­nesium citrate solution on the night before the enemamay well be adequate.

CONSTIPATION

Causes and Complications of ConstipationThere are three causes of constipation. The first is

functional and includes simple constipation, motility dis­orders such as hypotonic constipation (slow transit time),spastic colon (irritable bowel syndrome) and dyschezia('rectal' or 'habit' constipation), and psychiatric disorders.Constipation also occurs as a result of treatment, andmay be induced by drugs such as codeine, analgesics,alkalis (aluminium), cough mixtures and antidepressants,or by postoperative immobilization.

It may also be secondary to organic disease, and couldbe the result of anal, rectal, colonic and neighbouringlesions; anal fissures; a fistula or stricture; carcinoma ofthe rectum and colon; diverticulitis; rectal or uterine pro­lapse and sigmoid or other type of volvulu .

Jt could be caused by neurological disease such ashemiplegia or paraplegia, by disease of the endocrinesystem, e.g. hypothyroidism or diabetes, by a metabolicand toxic illness, e.g. debility and acute or chronic illness,or dehydration, or by other gastro-intestinal disease pre­senting with constipation.

The complications of constipation are faecal impaction,which leads to diarrhoea and incontinence; rectal bleedingcaused by piles or a stercoral ulcer; urinary retention;megacolon and volvulus; intestinal obstruction; restles­ness and confusion and cardiovascular effects due to forceddefaecation.

Functional Constipation

The term 'presbycolon' suggested by PaLmer to describethe wretched bowel malfunction of the elderly refers, inparticular, to constipation, distension and faecal impaction.It ranks with joint pain, dizziness, forgetfulness, depres­sion and bladder problems as one of the major causesof misery encountered in the aged.

Simple constipation. In elderly patients loss of musculartone, delay in transit time through the colon, diminishedrectal awareness and neglect of the need to defaecatecause a tendency to constipation. This tendency is aggra­vated by lack of variation of meals, decreased fibre intake,poor dentition, high cost of the correct foods, impairedmobility and poor fluid intake. Constipation is particularlylikely to occur with the added stress of a debilitatingdines and as a result of being confined to bed.

Psychiatric causes. Stresses are often aggravated in theaged because their resilience is low. Among the commonestencountered are loneliness, rejection by families, im­pending death, an incurable illness, forced retirement andfinancial worries. Depressive illness is particularly liableto be reflected by constipation, and these patients tendto reject the urge to defaecate.

Motility disorders. The hypotonic form is the mostcommon and is characterized by the late arrival of faecesat every point along the colon, with diminished water ab­sorption. The spastic bowel, on the other hand, manifestswith pain in the left or right iliac fossa, and the passageof hard cybala ('sheep droppings'). Dyschezia, due tolack of rectal awareness and impaired rectal emptying,is a rather less common cause of faecal impaction.

Carcinoma of the Rectum, Colon, Prostate or Uterus

The nihilistic attitude to the diagnosis, and, indeed, treat­ment of carcinoma in the aged is entirely incorrect. Clearly,there may be little point in pursuing an active diagnosticroutine in the severely debilitated patient or in thosewith diffuse metastases. The vast majority of aged patients,however, stand surgical intervention remarkably well withmodern anaesthesia and intensive care. Further, the symp­toms may be so unpleasant as to justify surgery despitethe increased mortality risk in such patients. Carcinomaof the rectosigmoid may 'cause rectal discomfort, leakageand bleeding, urgency and tenesmus, diarrhoea/ constipa­tion and even rectal or tumour prolapse, and more proxi­mal tumours may cause obstructive abdominal pain, dis­tension, diarrhoea and constipation, and eventual acute

26 March 1977 SA MEDICAL JOURNAL 411

obstruction. The presence of blood and/ or mucus in thestools, hypochromic anaemia, abdominal cramps and evenmelaena and alternatively hard and soft stools, are parti­cularly suggestive of carcinoma.

Failure to demonstrate a definite lesion by sigmoido­scopy or barium enema may warrant colonoscopy byan experienced colonoscopist. It is stressed that there are2 reasons for establishing the presence of carcinoma of thecolon or rectum; the high 5-year survival rate when therapyis given, in the case of early lesions, and the improvedquality of life after treatment, even in patients with meta­static disease.

Drug-Induced ConstipationMany drugs cause constipation and the aged patient

is more likely to be affected than a young person. Careshould be exercised when prescribing cough mixtures oranalgesics containing codeine or morphine and antacidscontaining anticholinergics, aluminium hydroxide and cal­cium. Many antidepressants of the amitriptyline grouphave an anticholinergic action and decrease the cerebraland rectal awareness of the urge to defaecate. Drugs forthe treatment of hypertension, Parkinson's disease, epilepsyand iron-deficiency anaemia, which are used less often,may cause constipation in individual patients.

Endocrine CausesIt is always worth considering the possible presence of

hypothyroidism in elderly patients with increasing con­stipation. Most patients with hypothyroid constipation willhave classic myxoedema; however, occasionally constipa­tion and abdominal distension dominate the clinicalpicture. The constipation usually responds to thyroxintherapy, but in the aged it is important to start with smalldoses, and to increase the dose gradually.

Other Gastro-Intestinal Diseases Presenting withConstipation

Gastroduodenal or pancreatic diseases, such as pepticulceration and carcinoma of the stomach and pancreas,not infrequently present with constipation, with or with­out pain, in the elderly. The constipation is usually due todecreased food and fluid intake, analgesic and alkali con­sumption, but reflex motility disorders may be the under­lying cause in some. Occasionally the constipation is re­lated to neoplastic involvement of the coeliac axis with im­paired bowel motility (Ogilvie's syndrome). For patientswith constipation associated with abdominal pain, a bariummeal examination may be necessary if a barium enemafails to reveal an abnormality.

Faecal ImpactionFaecal impaction should always be considered as a pos­

sible cause of constipation or diarrhoea in the aged. Inpatients with diarrhoea, the impacted mass may act as anobstructive ball valve, allowing proximal fermenting faecesto pass round it. Apart from the constipation/ diarrhoeasequence, patients may complain of (a) a feeling of rectalfullness, even after diarrhoeic bowel actions; (b) tenesmus;

(c) foul flatus; (d) abdominal distension; (e) sacral pres­sure; (j) leakage and soiling of underclothes, or even frankincontinence; (g) nausea and vomiting; (h) rectal bleedingdue to stercoral ulceration and (i) even intestinal ob­struction.

Although faecal impaction may occur at any age as aresult of sudden immobility, bed rest, or a change in dietor fluid consumption, it is particularly likely to occurin elderly patients who are confined to bed and who aretaking even small doses of constipating drugs.

Patients may give a history of constipation associatedwith a sensation of 'something in the rectum', frequent loosebowel actions, or the frequent passage of small amountsof rather putty-like stools - the so-called 'tooth-paste'impaction. Rectal examination will reveal a ballotable hardround mass, occupying most of the rectum, or multiplehard pellets, but the diagnosis may be less obvious in thecase of a 'tooth-paste' impaction, when the probing fingerwill encounter little more than a soft, putty-like stoolfilling the entire rectum.

The treatment is uncomfortable for the patient and un­pleasant and time-consuming for the doctor. Because ofthis, there is an understandable tendency to temporizewith the useless expedient of purgation or enemas, or todelegate manual rem.oval to the most junior nurse. Manualremoval demands skill, compassion and patience. Thereis no alternative but to break up and extract a solid faecalmass, or laboriously to remove 'tooth-paste' impactions,with or without proctoscopic or sigmoidoscopic piecemealremoval. Local anaesthesia is always necessary and pethi­dine analgesia is usually required to reduce the discomfortto the patient. General anaesthesia is sometimes warrantedin patients with a low pain threshold. Appropriate pur­gatives and suppositories, supplemented with enemas, aregiven for a few days after faecal disimpaction to ensurecomplete clearance.

TREATMENT OF CONSTIPATIONChronic constipation in the elderly is often the legacy ofa lifetime of bad bowel habits, coupled with physiologicalsluggishness of the colon. The condition is seldom curable,and it is as well to realize that patients may require ap­propriate aperients for an indefinite period. That thebowel can be re-educated is little more than a pious hope,but simple measures, such as increased dietary intake offibre such as bran, wholewheat bread, fruit and prunes,adequate fluids and fruit juices, physical exercise and thetreatment of depressive disorder are obviously important.

The decision as to which aperient should be used de­pends, to some extent at least, on the nature of the con­stipation. Patients with hypotonic constipation tend to havesoft stools and require colonic stimulants rather than stoolsofteners, whereas those with hard stools often benefitfrom the latter. Aperients are conventionally classified as(i) hydrophilic bulking agents (these are usually bran orthe seeds of various plants containing polysaccharides, egoNormacol (Petersen) , Isogel (Glaxo-AlIenbury), Metamucil(Searle), Agiolax (Intal), agar, etc.); (ii) stool ofteners, suchas liquid paraffin or dioctyl sodium sulphosuccinate; (iii)saline laxatives or hyperosmotics, such as magnesium saltsand lactulose; (iv) irritative or stimulating laxatives such

412 SA MEDIESE TYDSKRIF 26 Maart 1977

as enna, ca cara and polyphenoljc laxatives, such a phe­nolphthalein and bisacodyl.

Fairly enthusiastic purgation supplemented, if neces-ary, by glycerine or bi acodyl uppositories or enemas, is

occasionally necessary to empty the bowels of patientswith evere constipation. Once this is achieved, the idealis to ensure the passage of a daily bowel action. Patientshould be encouraged to relax on the toilet after breakfast

to take advantage of any ve tige of the gastrocolic reflexso important in younger people. The combination of ahydrophilic bulk purgative with sennosides A and B, Vera­colate (Warner) or cascara taken at night, an adequatefluid intake, and fruit juices and digestive bran sprinkledon a cereal or taken in orange juice in the morning maysuffice. The dose and type of aperient must, of course,be suited to the individual, and some patients may get thebest results with a seemingly unsuitable patent medicine.

Complications of therapy are rare and are usually re­lated to overdosage. Diarrhoea must be prevented. De­hydration and potassium loss, which lead to hypokalaemicweakness, are occasional hazards. High dosages of sennacompounds and bisacodyl may cause abdominal gripingand there have been reports that hydrophilic substanceshave caused bolus oesophageal obstruction in patientswith hiatus hernia. They are also reported to have causedintestinal obstruction proximal to obstructive colonic le­sions in patients with uch lesions, and, rarely, in patientswith hypotonic colonic disorder. Phenolphthalein may pro­duce a fixed skin eruption and the phytic acid in bran maybind ingested calcium salts. Overuse of purgatives maylead to the rare complication of cathartic colon. Greatcare should be exercised in the u e of anticholinergics,antidepressants and codeine compounds in elderly patientsand it is advisable to tart with the smallest dosages, e.g.amitriptyline 10 mg after lunch and 10 - 20 mg at night.

DIARRHOEA

The Causes of Diarrhoea in the ElderlyThere are about 100 possible causes of diarrhoea which

are listed in most conventional medical texts, and it is notpossible to deal with all or to present a uniform classifi­cation here. Among the common causes are 'stress-induced'or functional diarrhoea; infective and post infective diar­rhoea; colorectal carcinoma; inflammatory bowel disease;drug-indHced diarrhoea; diverticulitis; ischaemic colitis;dietary causes; endocrine and hormonal causes and faecalimpaction.

Functional or psychosomatic diarrhoea (spastic colon,mucou colitis, irritable bowel syndrome, stress-induceddiarrhoea).

Although constipation is a more common symptomthan diarrhoea, a significant number of aged patients tendto 'funnel their emotions' through the rectum. The diar­rhoea is usually typically colonic with early-morningdiarrhoea, hypogastric cramping and, not infrequently,mucoid stools. The onset may be related to acute stress.It may become protracted, or start insidiously, and theunderlying psychogenic factors will only be apparent afterin-depth con ultation with family and/or friends. Froma therapeutic angle aged patients require the ame, if not

greater, reassurance of the absence of serious organicdisease and explanation of the psychosomatic mechanismof the symptoms. Rectal examination will always be re­quired to exclude faecal impaction or a rectal lesion andthe extent of anxiolytic or antidepressive therapy must beassessed carefully, so that no undue harm comes to thepatient.

Infective and postinfective diarrhoea. As in other agegroups, the 3 important causes of infective diarrhoea in theelderly are food poisoning, bacterial infection by eitherSalmonella or Shigella species, or viral infection. The onsetis usually acute, with vomiting and diarrhoea, but diarrhoeamay be the only symptom. Whjle the presence of pyrexiaand toxicity suggests an associated bacteraemia or virae­mia, and their absence, an infection confined to the gut,the elderly often have a deficient response to infectionand the absence of pyrexia and toxicity does not excludethe possibility of a septicaemic phase. The hazard of acutediarrhoea is the rapid onset of dehydration, hyponatrae­mia or hypokalaemia and every effort must be made tocombat these effects, which may rapidly be fatal. As manyorganisms alter the bowel in such a way as to produce a'secretory type' of diarrhoea, the fluid loss into the bowellumen may be enormous. It is probably wise to start elderlypatients on an antibiotic such as co-trirnoxazole (Bactrim;Roche) or tetracycline once the stool culture has beentaken, and then to treat them with fluids, ·glucose, addedsalt and potassium, together with a costive agent.

Postinfective diarrhoea. This very common conditionis not well recognized, largely because we know so littleof its mechanism. Some patients, often those with a pasthistory of frequent bowel upsets or 'stress-induced diar­rhoea', develop persistent chronic diarrhoea for somemonths or even up to a year after a bout of bacterial orviral diarrhoea. A few patients develop lactose intolerancedue, presumably, to temporary derangement of theirmucosal enzymes. For the rest, one can only reassurethem as to the absence of serious disease and treatthem continuously with diphenoxylate or codeine phos­phate until the stools are normal. On no account shouldthe patient receive sequential and varied antibiotics ifthe stool culture is negative, since this only perpetuatesthe diarrhoea and makes it more difficult to determinethe aetiology. It is, however, usually necessary to carryout a few basic investigations to exclude other lesions,if only for patient and doctor reassurance. Secondaryanxiety or depression should be treated with appropriateanxiolytics or antidepressants.

Colonic and rectal carcinoma. Although colonic carci­noma usually results in recent or increasing constipationor alternating constipation and diarrhoea, it is not un­common for diarrhoea to be the only presenting symptomof the disease. This is particularly likely to occur whenthere are lesions in the caecum and ascendjng colon,where the colonic contents are till fluid, and in therectum when there is ll?akage of blood and mucus, andliquefaction of stool above a semi-obstructive lesion. There­fore, rectal lesions tend to present with frequent smallstools, whereas more proximal lesions manifest with alter­ation in bowel habit, iron-deficiency anaemia and occultblood in the stools.

SA MEDICAL JOUR AL

-26 March 1977

Rectal examination is mandatory in every patient withdiarrhoea, to exclude a mass or frank blood and to allowexamination of the stool for occult blood. Should theresult of either of these investigations be positive, therecan be no question that sigmoidoscopy and barium enemaare indicated. A barium enema may be perfectly normalin patients with rectal carcinoma, and igmoidoscopy isalways necessary in such cases.

Inflammatory bowel disease. Although ulcerative colitisand Crohn's disease are essentially diseases of the thirdand fourth decades, their onset may occur as late as theseventh and eighth decades. The symptoms do not differmaterially from those seen at earlier onset, namelydiarrhoea with the passage of blood, mucus, and often pus,frequently accompanied by rectal leakage, 'wet winds'and urgency and early morning 'rushes'. In the more acuteforms, there will usually be pyrexia and tachycardia, andthe patient may be extremely ill, toxic and dehydrated.Colonic Crohn's disease is typified by its anal manifesta­tions, and the presence of rectal fistulae, indurated skintags and perianal oedema with a violet hue should suggestthis diagnosis. The diagnosis is usually readily establishedby proctoscopy and sigmoidoscopy, which will show aninflamed, friable mucosa with Ulceration, bleeding andmucopus.

Amoebic colitis is excluded by rectal scrapings andmicroscopy at the time of sigmoidoscopy and infectivecolitis (Shigella, Salmonella) by immediate stool culture.Sigmoidoscopic findings may be indistinguishable fromthose of inflammatory bowel disease and it is always worthgiving a course of metronidazole and tetracycline to ex­clude them entirely. Ischaemic colitis affecting the rectummay be difficult to differentiate, but it is usually character­ized by considerable abdominal and rectal pain.

Acute inflammatory bowel disease is best treated inhospital with steroids, rehydration and careful observa­tion until the attack subsides. In localized forms treatmentwith sulphasalazine (Salazopyrin; Pharmacol), rectal pred­nisone enemas and a constipating drug will usually suf­fice; oral steroids should be reserved for acute flare-ups.At present it is recommended that sulphasalazine be con­tinued in a dose of 0,5 g 3 times a day for a periodof I year from the last attack. It is often difficult to dif­ferentiate between Crohn's disease and ulcerative colitisand, at best, the correct diagnosis is only achieved in some70% of patients with disease confined to the large bowel.

Ischaemic colitis. Aged patients are liable to vascularaccidents and occasionally the whole or a branch of themesenteric vessels becomes occluded. The diagnosis ofischaemic bowel disease is usually based on the acute onsetof diarrhoea, often with blood and mucus, in an aged,hypertensive or atherosclerotic patient. Fever, tachycardiaand abdominal tenderness are almost invariable. Becausethe area of infarction is more common in the transverse,descending or sigmoid colon, rectal examination andsigmoidoscopy will often be normal, apart from the im­portant finding of altered blood coming from above. Thedisease pattern varies from that of an acute abdominalemergency which requires almost immediate laparotomyto a subacute type which involves the mucosa and presents

8

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with cramps and diarrhoea. However, a barium enema iusually required to confirm the diagnosis and show pecu­lation of barium, narrowing of the calibre of the lumenand typical 'thumb-printing'. Later X-ray examinations willhow progres ive improvement, although ome patients

may be left with an area of fibrou narrowing of thebowel.

Diverticulosis and diverticulitis. Mo t patients with di­verticulosis tend to be constipated and in fact constipationis often mooted as the precipitating cause of diverticu­losis. The finding of diverticulosis i in it elf not a specificdiagnosis, for some 50% of patients over the age of 50years will be shown to have demon trable diverticula onbarium enema studies. The onset of diverticulitis is usuallyfairly typical, with left iliac fossa pain, pyrexia and a raisederythrocyte sedimentation rate and white blood cell count,and the diagnosis is rarely in doubt. However, aged patientsmay not always respond typically and a moulderingdiverticular or pericolic disease should be suspected if theattack does not subside rapidly after antibiotic therapy,or if the diarrhoea continues with low-grade pyrexia. Abarium enema may be hazardous at this stage and it isoften wise to persist with an antibiotic until clinical re­mission is achieved before doing it. It is important torecommend a high-bulk diet, a mild laxative and avoidanceof nuts to reduce the liability to subsequent attacks. Dif­ficulty may be experienced in detecting an associatedcarcinoma in an area of diverticulosis on barium enemaexamination and cv~n colonoscopy may fail to negotiatethe involved sigmoid colon.

Hormonal and metabolic disease. Of remediable causesof diarrhoea in the elderly, thyrotoxicosis or masked thy­rotoxicosis should be kept in mind. Although all theusual signs of thyrotoxicosis may be present, these areoften lacking and the only clue, apart from diarrhoea,may be tachycardia. It is worth pursuing thyroid investiga­tions in any patient with unexplained, non-infective diar­rhoea, particularly if the pulse rate is raised, or if weightloss and muscular weakness are features. Unexplainedauricular fibrillation makes investigation imperative. Dia­betic diarrhoea is relatively rare and usually implies a'gut neuropathy' in established diabetics. One distressingfeature is that the diarrhoea may wake the patient at night.The condition seldom responds to improved control of thediabetes and permanent treatment with a con tipatingagent is usually required. A course of antibiotic may behelpful. The rare possibility that the diabetes and diarrhoeamay be due to a pancreatic carcinoma, should be consider­ed. Uraemic colitis is particularly important in older menwith prostatic obstruction.

Parenteral infection. Elderly patient tend to re pond ina manner similar to children with regard to parenteral in­fections (and diarrhoea may be a manifestation of an in­fective process outside the confines of the gastro-intestinaltract, e.g. pyelonephritis, cholecystitis, pneumonia, etc.,and particularly postoperative intra-abdominal ep i . Py­rexia, no matter how minor, a raised edimentation rateor a moderately raised white cell count will provide animportant directive to the intensity of the search forparenteral infection or the necessity for 'blind' antibiotictherapy in the very ill or immobile patient.

A MEDIE E TVDSKRIF414

Drug-induced diarrhoea. Diarrhoea is the single mostommon side-effect· of drug idiosyncracy, toxicity or over­

dosage. A good adage i that almost very drug in thepharmacopoeia can produce diarrhoea, and the only wayto be quite ure of a causal relation hip is to withdrawadministration of the drug. Many elderly patients are takingdrugs for cardiovascular and other diseases and are fre­quently dependent on these drugs for comfort and urvival.There are, however, very few drugs that cannot be with­drawn for a short period so that the response can beassessed. The list of drugs which cause diarrhoea is for­midable, but a few require special mention.

(i) Purgatives: Many laxatives produce an osmoticdiarrhoea, but all purgatives may be incriminated. Theurreptitious use of purgatives is an even greater problem

and can only be established after a thorough investigation.(ii) Digitalis: The therapy of any patient taking a

digitalis preparation and who develops diarrhoea shouldbe discontinued for 24 hours and then restarted at half thedose. The whole scheme should be repeated if the diarrhoeai not controlled.

(iii) Antibiotic : All the available oral and even parent­eral antibiotics can cause diarrhoea by changing the 'gutflora' and the diarrhoea may continue for a considerabletime after therapy is discontinued. Occasionally, a frankpseudomembranous or ulcerative colitis ensues. These ef­fects have been reported as a result of the use of am­picillin and, in particular, clindamycin (Dalacin-C; Up­john).

Other Causes

The many other causes of mall-bowel diarrhoea whichmay produce malabsorption due to damage or infiltrationof the mucosa, lymphatic or vascular obstruction and im­paired bowel motility are relatively rare, and will probablyrequire pecialized investigations such as those for faecalfat, jejunal biopsy, disaccharide tolerance test, etc. Thefull list i to be found in any reputable textbook. Amoe­biasis, giardia is and worm are so common in all parts ofSouth Africa that piperazine citrate (Antepar) niclosamide(Yomesan; Bayer), and metronidazole (Flagyl; Maybaker)i justified in all patients with unexplained diarrhoea.

To conclude, there are two conditions which requireconsideration, since they can, at best, be treated accordingto symptoms:

(i) Bacterial overgrowth: Any condition which cau esbowel dilation or stasis, any patient who has had abdominalurgery and any patient who ha achlorhydria (the latter

two being common in the elderly) may develop an over­growth of bacteria in the mall bowel with resultingdiarrhoea. Treatment consists of tetracycline therapy, oftenintermittent, and an attempt to recon titute the normalflora with yoghurt, vitamin B complex or one of thevioform preparation.

(ii) Carcinoma of the pancreas may very occa ionallypresent with diarrhoea if the le iOR occurs in the proximalpancreatic duct. Careful attention to the history will revealthat the tool i teatorrhoeic, and although the underly­ing lesion is eldom curable, pancreatic extract will im­prove the diarrhoea.

26 Maart 1977

TREATME T OF DIARRHOEA

Specific di eases such as ulcerative colitis, carcinoma,lymphoma or tuberculosis need specific therapy. Lactoseintolerance requires the exclusion of dairy products (milk,cheese and butter) from the diet and the condition ofpatients who have undergone surgery may be improvedby the administration of hort courses of tetracyclineto combat bacterial overgrowth. Faecal impaction requiresremoval. Acute secretory or osmotic diarrhoea in the agednecessitates special attention to fluid losses and electrolytedepletion, to the point of intravenou replacement therapy,if the diarrhoea does not subside rapidly when the patientis given oral fluids and glucose.

If patients or their relatives note a relationship betweendiarrhoea and food idiosyncracy, the offending foodsshould be restricted, but apart from the removal of foodswith an obviou tendency to produce diarrhoea (milk, ex­cessive fruit, bread, etc.), dietary restriction should beminimized and the value of low-residue diets is highlyspeculative. In a few severe secondary diarrhoeas, it maybe necessary to use one of the newer but costly elementaldiets (e.g. Flexical (Mead-Johnson), Vivonex (SKF), Pre­cision (Wander-Sandoz» for a short time, because they arealmost completely ab orbed in the upper small bowel.

Most patients with secondary diarrhoea and the largegroup with functional diarrhoea of unknown aetiology,psychosomatic diarrhoea or irritable colon syndrome,will have to be treated symptomatically. Although there aremany kaolin- and pectin-containing liquid products on themarket which are highly effective in the milder diarrhoea,the simplicity of administration and the efficacy of thetablet costive agents justify their use. The well-tried groupof diphenoxylate and the codeine phosphate group are ex­tremely effective, and loperamide (Imodium; Ethnor) is arecent addition to the armamentarium. These preparationsshould be taken at a time when their action will coincidewith the maximum period of diarrhoea. Hence the large­bowel syndrome of early morning rushes is best treatedby administration of codeine phosphate (0,5 grain) orLomotil (Searle) at night, just before retiring, and after thefirst bowel action in the morning. Postprandial diarrhoea ibest treated by similar or larger doses half an hour beforemeals. These drugs should not be prescribed in a randomfashion. If abdominal cramps are a feature an antispa mo­dic may also be necessary and, again, it should be given tocoincide with the time of diarrhoea. Anticholinergic drugsshould be used with great caution in elderly male patientsbecause of the danger of precipitating urinary retention.It should be remembered that amitriptylines have an anti­cholinergic action and that sUlpiride (Eglonyl; oristan)may occa ionally cau e extrapyramidal side-effect.

BIBLIOGRAPHY

1. Bank, ., Saunders, S. J., Marks, I. . et al. in Avery, G. S., cd.(1976): Dr.ug Treatment, pp.. 506 - 561. sydney: Addis Press.

2. EXlon- milh, A. N., in Jones, F. A. and Godding, E. w. (1972):Management 0/ Constipation, pp. 156 - 175. London: Blackwell Scienti­fic Puhlications.

3. Fordtran, J. S. and Almy, T. P. in S1eisenger, M. H. and Fordtran,J. S. (1973): Gastrointestinal Disease, pp. 291 - 323 Philadelphia:W. B. Saunders.