For many people the suspicion that they are lactose intolerance is obvious – they suffer unpleasant digestive symptoms after eating dairy! However, sometimes the symptoms of lactose intolerance can be hard to distinguish from other conditions such as irritable bowel syndrome, so a diagnosis from a GP can be useful.
If you suspect you may have a milk allergy we strongly recommend that you avoid dairy altogether until you have seen a medical practitioner.
There are a couple of cheap and simple “tests” to help determine whether you are lactose intolerant – the first is to compare your symptoms after drinking lactose-free milk versus ordinary milk. Alternatively, purchase a trial pack of Lacteeze Extra Strength or Ultra tablets and compare your symptoms with and without Lacteeze. If your symptoms improve with lactose-free milk or after taking Lacteeze, then you can be fairly sure you are lactose intolerant.
If you are still unsure of the cause of your symptoms, then it may be worthwhile keeping a food diary for a couple of weeks. This involves listing exactly what you eat and when, along with a description of any symptoms you experience. The relationship between symptoms and dairy may become obvious and can be confirmed by your GP.
An alternative is to eliminate dairy from your diet altogether to see if symptoms improve, although it should be kept in mind that it takes some time for any accumulated lactic acid and gas in your gut to leave the body naturally (this can often take a week or more). For people who are severely lactose intolerant the answer may still not be clear as even small amounts of lactose hidden in foods or medications may still trigger symptoms. However, if symptoms improve and then re-appear when dairy is reintroduced then lactose intolerance is very likely.
After taking the above steps your doctor will probably be able to make a diagnosis based on the information you present. However, you may be asked to take one of the following tests in order to confirm the condition:
Hydrogen Breath Test
This is the most common test for lactose intolerance and is the most accurate. It measures the levels of hydrogen excreted in your breath after drinking a liquid high in lactose. You will be asked to avoid certain foods, medications and smoking before the test. During the test you will drink the high-lactose liquid and then your breath will be tested several times over the next few hours. High levels of hydrogen in your breath indicate that you may have lactose intolerance as any undigested lactose causes a build up of gasses including hydrogen. This test is non-invasive but if you are lactose intolerant you may experience some discomfort as a result of consuming high concentrations of lactose. The test is also not usually performed on babies and infants as it can cause severe diarrhoea.
This test involves measuring your blood sugar levels after consuming lactose. You will need to fast before the test. You will then drink a liquid high in lactose, after which blood samples will be taken every 30 minutes for 2 hours.
When lactose is broken down normally in the body it releases sugar into the blood. Therefore, blood sugar levels are expected to rise after lactose has been consumed. For people with lactose intolerance their blood sugar levels would remain relatively stable, indicating the body has not successfully broken down the lactose. As with the breath test, the blood test does involve consuming high concentrations of lactose, so discomfort may be felt by people who are lactose intolerant. Again, the test is also not usually performed on babies and infants as it can cause severe diarrhoea.
Stool Acidity Test
For infants and young children lactose intolerance may be diagnosed by measuring the amount of acid in a stool sample. For a child who has difficulty breaking down lactose the results would show higher acidity levels due to the presence of lactic acid and other fatty acids. Glucose may also be present.