How Can I Be Tested For A Lactose Intolerance?
There are three ways to test for lactose intolerance:
- The lactose tolerance test.
- The hydrogen breath test.
- The stool acidity test.
All of these tests are performed in a hospital, with your GP or at a clinic.
The Lactose Tolerance Test
If you have this test, you must not eat anything beforehand. Your doctor will give you a drink containing lactose and over the next two hours you’ll be monitored closely. During this time blood samples are taken to test if your body is breaking the lactose down properly.
The Hydrogen Breath Test
During the hydrogen breath test you’re given a drink containing lactose and your breath is analysed several times. If you’re intolerant there will be hydrogen present in your breath. This is caused by bacteria in your colon fermenting the undigested lactose.
In reality, a diagnosis for lactose intolerance is usually reached by an exclusion diet.Tanya Wright, Dietitian
Be warned: the accuracy of the hydrogen breath test can be compromised by eating other foods, smoking or taking certain medicines. Listen to your doctor’s advice to make sure the test is as reliable as possible.
The Stool Acidity Test
A stool sample can be analysed to detect lactic acid, which is caused by undigested lactose. This test is usually used for babies and young children who are suffering from temporary lactose intolerance following a bout of gastroenteritis.
Diagnosis Without A Test
In reality, tests are rarely carried out and a diagnosis is usually reached by an exclusion diet. You will be asked to gradually exclude and then reintroduce milk containing lactose, while keeping a food and symptom diary. If you think it could be lactose that's causing you discomfort, ask your GP to refer you to a dietitian.
Dr Adam Fox,
Tanya Wright , BSc hons, HPC registered,
Ria Campbell,
Ingredients and information are subject to frequent changes beyond our control – always be vigilant and seek medical advice if you have special dietary requirements.
