Investigation of diarrhoea in a traveller just returned from India

Learning points
The likely cause of travellers’ diarrhoea depends on the duration of symptoms
Bacteria, in particular enterotoxic Escherichia coli, are the most common pathogens found in travellers with acute symptoms (less than two weeks’ duration)
Stool microscopy for ova, cysts, and parasites and culture (ideally three specimens) form the key investigation in a patient who has just returned from travelling and has diarrhoea, although a causative agent is often not found
If symptoms persist, investigate for less common pathogens, such as parasites, and for non-infective causes