Diarrhoea is passing loose or watery faeces more than three times a day. It affects almost everyone from time to time and is usually nothing to worry about.

A common cause in both children and adults is gastroenteritis, an infection of the bowel. Gastroenteritis may be caused by:

• a virus, such as a norovirus or rotavirus
• bacteria, which is often found in contaminated food
• a parasite

See  Causes of diarrhoea for more information.

Bouts of diarrhoea in adults may also be brought on by anxiety or drinking too much coffee or alcohol. Diarrhoea may also be a side effect of a medication.

Recovery

In adults, diarrhoea caused by gastroenteritis will usually clear up in two to four days when the infection has cleared.

Taking antidiarrhoeal medicine is usually not necessary unless it is important that you shorten the length of time your diarrhoea lasts (for example, if you need to take a long-haul flight). Children should not take this medicine.

Diarrhoea in children usually passes within five to seven days, and will usually clear within two weeks. Seek medical advice if your child has diarrhoea for longer than this.

When to see your doctor

Diarrhoea in adults that lasts for more than a few weeks may be a sign of a more serious condition, such as Crohn’s disease. It should always .be investigated by your GP – especially if you have blood or pus in your faeces. It may indicate other conditions such as irritable bowel syndrome. See Causes of diarrhoea  for a full list of the conditions that can cause persistent diarrhoea.

If your baby or child has had six or more episodes of diarrhoea in the last 24 hours, see your GP. Diarrhoea can be serious in babies because of the risk of dehydration. See Diarrhoea – treatment for advice about treating the symptoms of diarrhoea and avoiding dehydration.