Acute diarrhoea

Diarrhoea is a common disorder, affecting all ages, and is a common cause for admission to hospital. A careful history often indicates the likely cause. Rarely, diarrhoea is the first presentation of a more chronic process. Careful examination combined with investigations help determine the disease severity. Stool culture positivity decreases each day following symptom onset, and stool cultures should be taken only during the first few days of symptoms. Stool examination for ova, cysts and parasites is indicated in the context of an appropriate travel or sexual history. Treatment of acute diarrhoea is often based on fluid and electrolyte replacement only. Antibiotics are rarely required and can prolong carriage of infective organisms. Clostridium difficile diarrhoea causes significant morbidity and mortality in elderly patients; novel treatments are required to prevent persistent disease. Flexible sigmoidoscopy and rectosigmoid biopsies are used to assist diagnosis in patients suspected of having inflammatory bowel disease.