Acute and Chronic Diarrhoea

7/27/2019 Acute and Chronic Diarrhoea

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ACUTE AND CHRONICDIARRHOEA

Prof. S.M. Bhatt, EBS,

MBCh.B, M.Med, MPH

(Hopkins), FRCP (Edin).

Professor of Medicine.



OUTLINE

Introduction.

Definitions. Classification of Diarrhea.

Approach to a patient with diarrhea.

Acute Diarrhea. Chronic Diarrhea.



Introduction

– Diarrhea is a major health concern in developing

countries.

– 4 billion global cases of diarrhea per year.

– It is one of the most common clinical signs of

gastrointestinal disease, but also can reflect

primary disorders outside of the digestive system

– Mainly affects <2 yr olds



Definitions

Diarrhea is best described as too frequentpassage of too loose (unformed) stools.

It is frequently accompanied by urgency, andoccasionally incontinence.

When considering a patient with diarrhea thefollowing must be considered: – frequency (>3 movements/day),

– consistency (loose/watery),

– volume (>200 g/day) and

– whether the condition is continuous.



Definitions

Acute : Diarrhea lasting less than 2 weeks,

Persistent : 2 to 4 weeks, and

Chronic –diarrhea lasting more than 4 weeks.

Dysentery : diarrhea with visible blood in the stool.

Pseudodiarrhea - frequent passage of small volumesof stool. Often associated with rectal urgency andaccompanies the irritable bowel syndrome or anorectaldisorders e.g. proctitis.

Fecal incont inence - involuntary discharge of rectalcontents, most often caused by neuromuscular disorders or structural anorectal problems



Classification

There are numerous causes of diarrhea though usually is amanifestation of one of the four basic mechanisms describedbelow.

It is common for more than one of the 4 mechanisms to beinvolved in the pathogenesis of a given case.1 . Osmotic Diarrhea: results if the osmotic pressure of

intestinal contents is higher than that of the serum.Characteristically, osmotic diarrhea ceases when the patientfasts. E.g. lactose intolerance

2. Secretory d iarrhea : occurs when there is a net secretion of water into the lumen. This may occur with bacterial toxins,such as those produced by E. coli or Vibrio cholerae, or withhormones, such as vasoactive intestinal polypeptide (VIP),which is produced by rare islet cell tumors of the pancreas.



Classification:

3. Inflammatory diarrh ea: results from direct damage to the

small or large intestinal mucosa. This interferes with the

absorption of sodium salts and water and is complicated byexudation of serum proteins, blood and pus. Infectious or

inflammatory disorders of the gut cause this kind of

diarrhea.

4. Dysm oti l i ty d iarrhea: Disorders in motility that accelerate

transit time could decrease absorption, resulting in diarrheaeven if the absorptive process per se was proceeding

properly.

NB: In most instances of diarrhea two or more of these four

mechanisms are at work.



Causes of Diarrhea

Infective causes

– Bacterial, e.g. Campylobacter

jejuni Salmonella sp. Shigella,

Clostridium botulinum GI TB

– Viral, e.g. rotavirus

– Fungal, e.g. histoplasmosis

– Parasitic, e.g. amoebic dysentery

(Entamoeba

histolytica) schistosomiasis Giardia

intestinalis

Endocrine

– ZE syndrome

– Vipoma

– Carcinoid syndrome

– Thyrotoxicosis

– Medullary carcinoma of thyroid

– Diabetic autonomic neuropathy

Non-infective causes of diarrhoea

– Inflammatory bowel disease

– Pseudomembranous colitis – Radiation proctitis or colitis

– Behçet's disease Diverticular disease

Ischaemic colitis

– Malabsorption

– Drugs - many,

including laxatives metformin antica

ncer drugs – Irritable bowel syndrome and functional

diarrhoea

Factitious diarrhoea

– Purgative abuse

– Dilutional diarrhoea



Approach to a patient with

Diarrhea.

History:

–

Is it truly diarrhea? Duration? – The stool: consistency?, frequency?, volume? any

visible blood?.

– Any systemic symptoms :Fever, tachycardia,

weight loss? – Underlying Risk factors: Age, immune status,

recent travel, medications, known food allergy?

– Presence and location of abdominal pain?



Approach to Diarrhea

Physical exam inat ion : Always look for signs

of dehydration and malnutrition. – Vital signs: tachycardia, hypotension, tachypnea.

– Skins turgor and tonus.

– Systemic features of any underlying disaese e.g.

stigmata of HIV. – Abdominal exam: distension, bowel sounds,

tenderness, masses and rectal examination



Approach to diarrhea patient.

Laboratory and diagnostic studies: chosen on the history, acute

vs. chronic diarrhea.

Stool analysis: – Microscopy: for features of intestinal inflammation.

– Ova and Cyst.

– Toxins like C.deficile

–

Culture. – Quantitative and qualitative fat analysis.

FHG, LFTs and U/E/CR

Imaging as per the clinical presentation of the patient.



Acute Diarrhea

More than 90% of cases of acute diarrhea are

caused by infectious agents; these cases are often

accompanied by vomiting, fever, and abdominalpain.

The remaining 10% or so are caused by

medications, toxic ingestions, ischemia, and

other conditions. In immunocompetent patients it is usually self

limiting and intervention may be limited to oral

rehydration if there are no signs of significant fluid

loss.



Acute diarrhea: Presence or

absence of blood in stool

Acute diarrhea with blood

Bacillary dysentery (shigellosis)

Enterohemorrhagic EC

Campylobacter

Salmonella

Yersinia

Amebic dysentery

Pseudomembranous colitis.

Acute dirrrhea without blood

Viruses(Rotavirus etc)

Bacteria:

– Cholera;

– E.Coli except EHEC;

– Clostridia

Protozoa:

–

Giardia; – cryptosporidia.

Others:

– Food toxins,

– strongloides;

– malaria



Acute diarrhea: site involved

Small bowel

Include toxigenic bacteria like

vibrio and ETEC; viruses andGiardia.

Produce large volume watery

diarrhea and mid abdominal

pain.

Blood and fecal leucocytes are

rare.

Large bowel

Usually invasive oerganisms

like Shigella, campylobacter and EIEC, EHEC.

They produce low volume,

mucoid or bloody diarrhea.

Associated with low abdominal

or rectal pain (tenesmus). There is inflamed rectal mucosa

and the diarrhea has fecal

leucocytes



Acute diarrhea: management

Fluid replacement:

– Oral rehydration is preferred route but if patient vomiting or

intravascularly depleted (resting tachycardia with posturalhypotension) IV fluid is necessary.

Diet: Not benefit to fasting but avoid the following:

– Dairy products

– Alcohol

– caffeine



Acute diarrhea: management

Drugs:

–

Antimoility agents: Can be very useful but should not be used if there is an

acute severe colitis. LOPERAMIDE is the drug of

choice.

– Antibiotics: Indications-

Pathogens: shigella; V.cholera, S.typhi; C.deficile.

Acute diarrhea with pain, vomiting, fever and myalgia.

Laboratory proven cases of G.intstinalis.

Traveller’s diarrhea in adults.



Chronic diarrhea

History

– To distinguish:

Acute from chronic diarrhea Organic (<3months; weight loss; nocturnal symptoms;

continuous symptoms) from functional(absence of organic

symptoms and longstanding history)

Malabsorptive diarrhea ( bulky, malodorous, difficult to flush,

pale stools) from other causes(liquid/loose stools with blood or

mucus)

– Stool character and associated symptoms.

– Family history of IBD

– Sytemic dideseases e.g DM and hyperthyroidsm

– Evidence of chronic pancreatitis.

– Diet and stres as aggreveating factors



Chronic diarrhea

Physical exam:

–

General exam: extent of fluid depletion; nutritionalstatus.

– Skin and mucus membranes: Rashesmouth

ulcers etc

–

Thyroid gland exam – Per Abdomen: Ascites, masses

– Anorectal exam for abscesses, masses etc.



Chronic Diarrhea

Investigations:

– Blood tests: FHG/ESR; Fe and B12, TFT, RBS, LFTS, U/E/CR

– Stool: m/c/s

For fat analysis

Stool volume and osmotic gap response to fasting

– Sigmoidoscopy and/or colonoscopy

– Radiological imaging. – Others:

Pancreatic function test.

Small bowel biopsy

Serology for coeliac disease.



Chronic diarrhea: treatment

Treatment of chronic diarrhea depends on the specific etiology and

may be:

–

Curative: If the cause can be eradicated, treatment is curative aswith antibiotic administration for Whipple's disease, or

discontinuation of a drug.

– Suppressive: For many chronic conditions, diarrhea can be

controlled by suppression of the underlying mechanism. Examples

include elimination of dietary lactose for lactase deficiency or

gluten for celiac sprue, use of glucocorticoids or other anti-inflammatory agents for idiopathic IBDs or

– Empir ical : When the specific cause or mechanism of chronic

diarrhea evades diagnosis, empirical therapy may be beneficial.

Mild opiates, such as diphenoxylate or loperamide, are often

helpful in mild or moderate watery diarrhea.

Acute and Chronic Diarrhoea

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