Lactose Intolerance: Tests and Diagnosis

What tests are used to diagnose lactose intolerance?

Specific tests that assess lactose intolerance include the lactose hydrogen breath test and measurement of enzyme levels on small intestine tissue that is sampled during an upper intestinal endoscopy procedure.

Why choose Children’s Hospital Colorado for lactose intolerance tests?

Children’s Colorado’s Digestive Health Institute has the most up-to-date diagnostic tests for lactose intolerance and our providers are experienced with the diagnosis and treatment of lactose intolerance.

What to expect from lactose intolerance tests?

The lactose hydrogen breath test is a non-invasive test where the patient consumes a lactose-containing liquid. Every 30 minutes after drinking lactose for a total of three hours, the amount of hydrogen in the breath is measured by blowing into a machine. Higher levels of hydrogen that develop between one to three hours after ingestion indicate poorly digested sugar in the gastrointestinal tract. Specific enzyme levels, including lactase, can be measured in the intestinal lining and this requires an intestinal biopsy obtained during endoscopy.

How do doctors at Children’s Colorado make a diagnosis?

Frequently, a diagnosis of lactose intolerance is made on the history that a patient readily develops symptoms between one to three hours after consuming dairy products. If the diagnosis is not clear, tests such as the lactose hydrogen breath test may be ordered.