What are the symptoms of food intolerance?

Symptoms may start minutes or several hours after eating and can vary with the amount consumed. Bloating, cramps, excess wind, loose stools, nausea and changes in bowel habit are common patterns. Some people notice symptoms only after repeated exposure or when several foods are eaten together, which can make the trigger difficult to identify.

Food intolerance is different from an immediate immune reaction such as a food allergy. A food diary can show timing and patterns, but symptoms alone cannot confirm the cause. Irritable bowel syndrome, coeliac disease, infection and other digestive conditions can feel similar.

Record the food, portion, timing and symptoms for a short period, including medicines and other meals. Avoid making broad, long-term exclusions without advice because this can reduce nutritional variety. A clinician may recommend food intolerance testing or a structured elimination and reintroduction plan. Nutrition counselling can help keep meals balanced while a trigger is assessed.

Arrange medical advice for persistent diarrhoea, ongoing pain, unexplained weight loss, blood in the stool, repeated vomiting, fever, or symptoms that wake you at night. Facial swelling, wheezing or throat tightness after food suggests possible allergy rather than simple intolerance and needs urgent assessment.

Ask whether your pattern fits intolerance, allergy or another digestive condition. Discuss which tests are useful, whether a supervised food challenge is needed, and how to replace nutrients if a food must be limited.