Diarrhoea straight after eating

Eating naturally signals the colon to move waste along, so an urgent bowel movement may follow a meal even when that meal has not yet passed through the whole digestive system. Repeated episodes may be linked with Irritable Bowel Syndrome, Food Intolerance, or Coeliac Disease. Sudden diarrhoea with vomiting, cramps, or fever can occur with Food Poisoning or Gastroenteritis. Ongoing symptoms with weight loss, tiredness, blood, or night-time waking need a clinician's assessment; Crohn's Disease and an overactive thyroid are among conditions they may consider.

Drink frequent small amounts of water or an oral rehydration drink. Eat when you feel able, choosing simple foods such as rice, bread, potatoes, bananas, soup, or yoghurt if dairy does not worsen symptoms. Keep a brief diary of meals, urgency, stool changes, pain, medicines, and travel. Do not repeatedly remove major food groups without advice, and wash your hands carefully after using the toilet.

Seek urgent medical help for severe dehydration, fainting, confusion, severe abdominal pain, black or bloody stools, or repeated vomiting that prevents drinking. Arrange medical advice if diarrhoea keeps returning after meals, lasts beyond a short illness, wakes you at night, or comes with fever, weight loss, or marked weakness. Children, older adults, pregnant people, and anyone with a long-term illness may need advice sooner.

Could the pattern fit a food intolerance or Irritable Bowel Syndrome? Do I need stool or blood tests? Which foods should I continue eating while symptoms are investigated? What signs mean I should seek same-day help?