What should you know about diarrhoea?

Loose stools can follow an infection, contaminated food, a medicine, food intolerance or a change in eating pattern. Recurrent or ongoing symptoms may occur with irritable bowel syndrome, coeliac disease, Crohn's disease, giardiasis or an overactive thyroid. The symptom does not identify one cause by itself. The timing, stool appearance, pain, fever, travel, medicines and weight change help a clinician narrow the possibilities.

Drink frequently; oral rehydration solution can replace water and salts when stools are frequent. Eat small, simple meals as tolerated and avoid alcohol. Wash hands carefully, clean bathroom surfaces and avoid preparing food for others while an infection is possible. Do not start antibiotics or anti-diarrhoeal medicine without advice, especially if there is blood, fever or significant abdominal pain. Keep a brief record of triggers and stool changes if episodes recur.

Seek urgent help for blood or black stools, severe abdominal pain, confusion, fainting, repeated vomiting, inability to drink, very little urine or signs of marked dehydration. Arrange a clinical review for diarrhoea that keeps returning, follows travel, occurs with weight loss, wakes you at night or does not settle. Children, older adults and people with long-term illness may need earlier advice.

Ask whether you need stool tests, whether a medicine or food could be contributing, which fluids are suitable, and what symptoms should prompt immediate reassessment.