Food intolerance: symptoms, causes, and testing
What is food intolerance?
Food intolerance means difficulty digesting or tolerating certain foods or ingredients. It often causes digestive symptoms after eating. Lactose intolerance, for example, happens when the body produces too little lactase, the enzyme that breaks down milk sugar. Food intolerance is different from food allergy and celiac disease.
Common food intolerance symptoms
Bloating, gas, stomach pain, and diarrhea can occur after eating. Timing and severity vary with the food, portion size, and individual. These symptoms can also have other causes.
Explore food intolerance symptomsWhat causes food intolerance?
Some reactions involve difficulty digesting a particular ingredient, such as lactose. Keep a food and symptom diary to discuss patterns with a clinician rather than assuming one food is responsible.
Understand lactose intoleranceFood intolerance testing options
Testing depends on your symptoms and the suspected condition. Options include a clinical history, a guided dietary trial, and breath testing for lactose malabsorption. Food IgG panels measure antibody levels but are not established diagnostic tests for intolerance or allergy.
Compare food intolerance testing optionsSources: NHS food intolerance guide and our reference library. Educational information, not an individual diagnosis.