Bloody diarrhoea is an uncommon symptom in children, and it may indicate the presence of serious disease. This review focuses on children presenting in a primary care setting. The non-specialist should be aware of the likely causes, initial management, and indications for specialist referral. The emphasis is on children in the developed world, although traveller’s diarrhoea is also considered. The epidemiology and management of this condition are different in the developing world, where infectious causes predominate. In recent years the reported incidence of inflammatory bowel disease increased greatly in the developed world and important advances have been made in its management. This diagnosis should always be considered carefully.