Traveller's diarrhoea is common. But it is difficult to put a percentage on it as a lot depends on lots of different factors. However, we do know that traveller's diarrhoea can be serious and can cause complications - from lactose intolerance to irritable bowl syndrome.

To find out more, please have a listen to this podcast with Daniel Leung, Professor at the Division of Infectious Diseases, Dr Thomas D. Rees and Natalie B. Rees Presidential Endowed Chair in Global Medicine University of Utah School of Medicine.

For more on traveller's diarrhoea, visit BMJ Best Practice.

Competing interests: DTL receives authorship royalties from UpToDate, Inc, for a chapter on travel medicine; is an author of upcoming chapters on traveller's diarrhoea for the US CDC Yellow Book; is the past president of the American Committee on Clinical Tropical Medicine and Travelers' Health - Clinical Group within the American Society of Tropical Medicine and Hygiene; and is an author of some of the references cited in this topic.