What should you know about exploding diarrhoea?

A brief episode may follow a stomach infection, food poisoning, or a food intolerance. Gastroenteritis can bring watery stools, cramps, vomiting and fever. Persistent or recurring diarrhoea may also occur with irritable bowel syndrome, coeliac disease, Crohn's disease, giardiasis or an overactive thyroid. The symptom alone does not identify its cause.

Fluid and salts leave the body with each watery stool. Thirst, a dry mouth, dizziness, tiredness and passing urine less often can signal dehydration. Children, older adults and people with long-term illness can become unwell more quickly.

Take frequent small sips of water or an oral rehydration drink. If you feel sick, sip slowly rather than drinking a large amount at once. Eat light foods when you can, such as rice, toast, soup or bananas; avoid alcohol and foods that clearly worsen symptoms.

Wash your hands with soap and water after using the toilet and before preparing food. Do not prepare food for other people while you have diarrhoea. Note when it began, how often it happens, any blood or fever, recent travel, new medicines and possible food triggers.

Seek urgent medical help for fainting, confusion, severe weakness, severe abdominal pain, bloody or black stools, repeated vomiting that prevents drinking, or signs of serious dehydration. Contact a clinician promptly if diarrhoea is persistent, keeps returning, follows recent antibiotics or travel, or affects a young child, older adult or person with a weakened immune system.

Ask what cause is most plausible, whether you need stool or blood tests, how much fluid to take, and which medicines should be avoided. Tell the clinician about recent travel, antibiotics, pregnancy, long-term conditions and any blood, fever or weight loss.