Diarrhoea - Clinical Symptoms

Diarrhoea

Diarrhoea is the abnormal passage of loose or liquid stools more than three times daily and/or a volume of stool greater than 200 g/day. Patients may use the term diarrhoea in different ways. Diarrhoea lasting for more than 4 weeks is generally considered chronic, likely to be of noninfectious aetiology and warrants further investigation.

Acute diarrhoea occurs with viral gastroenteritis, food poisoning and traveller’s diarrhoea. Other symptoms such as pain, fever and vomiting may be present. In most cases specific treatments are unnecessary; however, adequate hydration (preferably using oral rehydration solution) is essential.

Chronic diarrhoea may be caused by organic or functional bowel disorders (e.g. irritable bowel syndrome). Functional bowel disease tends to cause a prolonged history of intermittent diarrhoea, without weight loss. It should be noted however that patients with inflammatory bowel disease might present in this way. Organic disease is suggested by a history of diarrhoea of less than 3 months duration, continuous or nocturnal diarrhoea, or significant weight loss. Malabsorption often causes steatorrhoea (stool that is frothy, foul smelling and floats because of a high fat content).

History taking in chronic diarrhoea should include the following:

·        Previous gastrointestinal surgery.

·        Any coexistent pancreatic, endocrine or multisystem disease.

·        Family history of gastrointestinal neoplasia, inflammatory bowel disease or coeliac disease.

·        Medication including previous antibiotics.

·        Foreign travel.

Screening tests should include full blood count, ESR, CRP, urea and electrolytes, liver function tests, calcium, vitamin B₁₂, folate, iron studies, thyroid function tests and coeliac serology. Infectious chronic diarrhoea is uncommon in non-immunocompromised patients; how-ever, stool cultures and microscopy should also be sent.

In young patients (under 45 years) with symptoms suggestive of functional bowel disease, a normal examination and negative screening tests, no further investigations are required. If atypical findings are present, a sigmoidoscopy should be performed. In older patients colonoscopy with ileoscopy should be performed with biopsy and histological examination of any suspicious areas.