Diarrhoea during or after intense exercise (most frequently running) is often referred to as 'runners trots'.
The cause of diarrhoea is unknown although a combination of intestinal ischemia (lack of blood flow), changes in secretion and absorption and increased intestinal movement may be to blame. Other contributing factors in athletes may be the use of certain supplements (vitamins, minerals, caffeine etc).
The treatment of exercise-induced diarrhoea may include dietary changes to reduce fibre intake before exercise and if this is not effective, the use of anti-diarrhoea medicines. This should not, however, be used on a regular basis.