Parasitic causes of prolonged diarrhoea in travellers - diagnosis and management.

BACKGROUND Prolonged infectious diarrhoea in the returning traveller is generally caused by protozoal and occasionally by helminth parasites. OBJECTIVE This article provides a framework for the diagnosis, management and prevention of the diseases that cause persistent diarrhoea in the traveller. DISCUSSION A large proportion of disease is caused by Giardia lamblia, Cryptosporidium parvum and Entamoeba histolytica. However, given the ease of travel with comorbid conditions such as human immunodeficiency virus, there is an expanding list of organisms that can cause persistent diarrhoea. An awareness of the likely aetiological agents and their clinical features enables a more effective diagnosis and management of the patient's condition using an appropriate antiparasitic agent. Prevention strategies need to be initiated before travel and should consist of simple but memorable advice. Noninfectious causes of diarrhoea should be considered as diarrhoea can be a prominent feature of conditions such as hyperthyroidism or coeliac disease.