Diarrhoea may be a symptom of a disease requiring surgical intervention (acute appendicitis, intestinal obstruction, cholecystitis). Diarrhoea may occur concomitantly with a more serious infection (malaria, bacterial meningitis, septicaemia). Patients with a curable infection (e.g. bacterial diarrhoea, Clostridium difficile colitis) should be identified and treated on the basis of history and clinical examination. A swift and systematic approach is required when there is a suspicion of a food- or water-borne epidemic.