Digestive System Home > Lactose Intolerance Testing
Some of the tests used to diagnose lactose intolerance include the hydrogen breath test, the lactose tolerance test, and the stool acidity test. While a doctor can use these tests to make the diagnosis, he or she may first recommend eliminating cow's milk from the diet to see if the symptoms go away.
Lactose intolerance can be hard to diagnose based on symptoms alone. People sometimes think they are lactose intolerant because they have the symptoms associated with lactose intolerance; what they may not know is that other conditions, such as irritable bowel syndrome or a milk allergy, can cause similar symptoms.
In order to diagnose lactose intolerance, a doctor will ask a number of questions about a person's symptoms, perform a physical exam, and recommend certain tests. While a doctor can use these tests to diagnose lactose intolerance, he or she may first recommend eliminating cow's milk from the diet to see if the symptoms go away.
Lactose intolerance testing measures the absorption of lactose (milk sugar) in the digestive system. Common tests used to diagnose lactose intolerance include:
- Lactose tolerance test
- Hydrogen breath test
- Stool acidity test.
Lactose Tolerance Test
The lactose tolerance test requires fasting (not eating) before the test and then drinking a liquid that contains lactose. Several blood samples are then taken over a two-hour period to measure the person's blood glucose (blood sugar) level. These measures indicate how well the body is able to digest lactose.
Normally, when lactose reaches the digestive system, the lactase enzyme breaks it down into glucose and galactose. The liver then changes the galactose into glucose, which enters the bloodstream and raises the person's blood glucose level. If, however, lactose is incompletely broken down, the blood glucose level does not rise, and a diagnosis of lactose intolerance is confirmed.