Travellers' diarrhoea is the most common travel-related ailment. The cornerstone of prevention is food and water precautions, as described in the issue general information. All travellers should bring along an antibiotic and an anti-diarrhoea drug to be started promptly if significant diarrhoea occurs, defined as three or more loose stools in an 8-hour period or five or more loose stools in a 24-hour period, especially if associated with nausea, vomiting, cramps, fever or blood in the stool. Most cases of travellers' diarrhoea are mild and do not require either antibiotics or anti-diarrhoea drugs. Adequate fluid intake is essential.