Food Intolerance

Last Updated: July 3, 2026

Key Points

Difficulty digesting certain foods or ingredients
Symptoms appear hours after eating trigger foods
Not an allergic reaction involving the immune system
Commonly causes digestive discomfort

Overview

A food intolerance means your body struggles to properly digest certain foods or ingredients. Unlike a food allergy, it doesn't involve your immune system and is typically not life-threatening, though it can cause significant discomfort. It happens when your body can't break down specific components of food, such as lactose in dairy or gluten in wheat. This digestive difficulty leads to various uncomfortable symptoms that can last for hours or even days after eating. Managing food intolerance usually involves identifying and reducing or avoiding the trigger foods. It's important to do this under medical guidance to ensure you still get all necessary nutrients, especially for children.

Signs and Symptoms

Diarrhoea
Bloating
Farting
Tummy pain
Headache
Feeling tired or exhausted
Nausea
Constipation
Joint pain
Rashes

Things That Increase the Risk

Genetic factors (e.g., for lactose intolerance)
Enzyme deficiencies (e.g., lactase deficiency)
Consumption of specific food ingredients (e.g., gluten, histamine)
High intake of certain foods (e.g., caffeine, alcohol)

Diagnosis

Referral to a food and nutrition specialist (dietitian)
Elimination diet (avoiding suspected foods)
Reintroduction of foods to observe symptom return
Blood tests
Breath test (for lactose intolerance)
Keeping a food and symptoms diary

Treatment & Management

Avoid or reduce trigger foods and ingredients
Consult a GP or dietitian before cutting foods
Ensure a balanced diet to prevent nutrient deficiencies
Monitor symptoms with a food diary

Prevention

Identify specific trigger foods
Carefully manage dietary intake
Read food labels for ingredients
Seek professional dietary advice
Avoid unproven home tests

Available Treatments

Explore our range of treatment options for Food Intolerance: