When is food intolerance testing recommended for irritable bowel syndrome?

IBS can cause abdominal pain, bloating, diarrhoea, constipation, or changes between bowel habits. Several foods and eating patterns may aggravate symptoms, but a reaction after eating does not by itself prove an intolerance. A clinician first considers the symptom pattern, medicines, infections, coeliac disease, inflammatory bowel disease, and other explanations. Some commercial panels have limited clinical value, so the useful question is whether a particular test can answer a specific concern.

Keep a short diary recording meals, portions, symptoms, bowel changes, and timing. Take it to a GP or dietitian rather than removing many foods at once. They may suggest a structured elimination and reintroduction plan, with attention to fibre, fluids, and nutritional balance. Do not remove gluten before discussing coeliac testing, because this can affect the assessment. A dietitian can help prevent unnecessary restriction when several foods seem linked to symptoms.

Arrange medical review for blood in the stool, unexplained weight loss, persistent fever, anaemia, symptoms that wake you at night, a new change in bowel habit, or a strong family history of bowel disease. Seek urgent help for severe or rapidly worsening abdominal pain, repeated vomiting, a swollen abdomen with inability to pass stool or gas, or signs of dehydration.

Ask which diagnoses should be excluded, whether a specific test is appropriate, how long a dietary trial should last, and how to maintain adequate nutrition while checking suspected triggers.