Food intolerance

A food intolerance is when you have difficulty digesting certain foods. Symptoms usually start a few hours after eating and depend on how much you eat. Common examples are lactose in milk, wheat, and some additives. It does not involve the immune system, so it is different from a food allergy.

Last updated Nov 9, 2026

What it is

Keeping a food diary and cutting out a suspected food for a while, then bringing it back, can help identify the cause, ideally with advice from a doctor or dietitian.

Many people can still eat small amounts of the food without symptoms.

Common signs

  • Bloating
  • Tummy pain
  • Wind
  • Diarrhoea
  • Skin rashes or itching, sometimes

How it is usually diagnosed

  • A food diary
  • Elimination and reintroduction of foods
  • Tests to rule out coeliac disease or allergy

Records worth keeping

Keeping these together makes each appointment easier, especially when you see a new doctor:

  • Food and symptom diaries
  • Test results
  • Dietitian advice

Questions to ask your doctor

  • Could this be an allergy or coeliac disease?
  • Should I see a dietitian?
  • How much of this food can I eat?

When to get help right away

Call 112 or go to the nearest emergency department if you have:

  • Swelling of the lips or throat, or difficulty breathing after eating: call 112, it may be an allergy

This page is general information. It is not a diagnosis and does not replace a doctor who knows your history. Medfold keeps your records organised; it does not interpret them.

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