What should you know about IgA food intolerance test?

IgA is an antibody found in the blood and at surfaces such as the gut. A test may be ordered as part of a wider assessment when symptoms such as bloating or diarrhoea occur after eating. A result needs to be matched with the timing of symptoms, the foods involved, your examination and other tests. A positive result does not automatically prove that a food is causing symptoms, and a negative result does not explain every digestive problem. Food intolerance is different from an immediate food allergy, which can involve a rapid immune reaction.

Write down meals, symptoms, medicines and their timing for a short period before your appointment. Do not remove many foods for a long time without professional guidance, because restrictive eating can reduce nutritional variety. A clinician may suggest a structured elimination and reintroduction plan, or a more suitable investigation. A registered dietitian can help protect adequate nutrition while you test a suspected trigger; see [Nutrition Counselling](/treatments/lifestyle-and-wellness/nutrition-counselling/). Learn about [Food Intolerance Testing](/treatments/diagnostics-and-screening/food-intolerance-testing/) and the broader condition at [Food Intolerance](/conditions/food-intolerance/).

Arrange medical review if digestive symptoms keep returning, interfere with eating, or come with weight change, persistent vomiting, blood in the stool or signs of dehydration. Seek urgent help for trouble breathing, faintness, or swelling of the lips or tongue after eating, because those features may signal a severe allergic reaction rather than food intolerance. Read about [Bloating](/symptoms/bloating/) and [Diarrhoea](/symptoms/diarrhoea/) for symptom-focused guidance.

Ask which antibody is being measured, whether the test is appropriate for your symptoms, and what a positive or negative result would change. Ask how to investigate other causes and whether you need a supervised food trial or dietitian support.