What should you know about prolonged diarrhoea?

Diarrhoea may follow an infection such as gastroenteritis or food poisoning, but symptoms that continue can also relate to food intolerance, coeliac disease, irritable bowel syndrome, Crohn's disease, giardiasis or an overactive thyroid. The pattern matters: tell a clinician how often you pass stools, whether they are watery, and whether pain, bloating, fever, vomiting, weight change or blood is present. Prolonged symptoms do not identify one condition on their own.

Drink frequent small amounts of water or an oral rehydration drink, especially after each loose stool. Continue eating light foods that you tolerate, and avoid alcohol and foods that clearly worsen symptoms. Wash hands carefully and avoid preparing food for others if an infection is possible. Record stool changes, meals, travel, new medicines and any sick contacts. Arrange a medical review if the problem continues, returns repeatedly, or is affecting daily activities; the clinician may ask for stool or blood tests based on your history.

Seek urgent help for severe weakness, confusion, fainting, very little urine, inability to keep fluids down, severe abdominal pain, or blood or black stool. A high fever, signs of dehydration, or diarrhoea in a young child, older adult, pregnant person, or someone with a weakened immune system also warrants prompt advice. Do not wait for symptoms to become severe before arranging assessment.

Ask what causes fit your symptom pattern, whether you need stool or blood testing, which drinks and foods are suitable, and whether any medicine should be paused or changed. Mention recent travel, untreated water, antibiotics, long-term conditions and family bowel problems.