Cold diarrhoea: possible causes and what to do

Loose or watery stools may occur during gastroenteritis or food poisoning, sometimes alongside tiredness, nausea, fever, or body aches. A respiratory cold does not typically explain diarrhoea by itself, although infections can overlap and medicines can upset the bowel. Repeated or longer-lasting symptoms can also be linked with food intolerance, irritable bowel syndrome, coeliac disease, Crohn's disease, giardiasis, or an overactive thyroid. The pattern, recent food or travel exposure, and any blood or pain help guide assessment.

Take frequent small sips of water or an oral rehydration drink, especially after each loose stool. Eat light foods when you feel able and avoid alcohol and foods that clearly worsen symptoms. Wash hands carefully and avoid preparing food for others while unwell. A pharmacist can advise about symptom relief, but do not use anti-diarrhoeal medicine without advice if you have blood in the stool, a high temperature, or significant abdominal pain. Children, older adults, and people with long-term illness can become dehydrated more quickly.

Seek urgent medical help for severe dehydration, fainting, confusion, severe abdominal pain, black or bloody stools, or inability to keep fluids down. Arrange assessment when diarrhoea is persistent, keeps returning, follows travel, or occurs with weight loss, ongoing fever, or marked weakness. A clinician may ask about medicines, food exposures, bowel changes, and hydration before deciding whether tests are needed.

Ask which fluids are suitable, whether a medicine could be contributing, how long home care is reasonable, and whether your symptoms fit infection, intolerance, or an ongoing bowel condition.