Diarrhoea is defined as the frequent passage of loose or watery stools. Most patients can easily recognise and accurately define acute diarrhoea as an abrupt change in their bowel habits. Chronic or recurrent diarrhoea is more difficult for the patient to define, since it may mean malabsorption, tenesmus or true diarrhoea. Serious disorders not to be missed include neoplasia, AIDS, various serious infections such as amoebiasis, and inflammatory bowel disease.