Lactose Intolerance / Lactose Malabsorption Breath Test

Millions of individuals are lactose intolerant. With symptoms such as abdominal pain, bloating, gas, and diarrhea, patients experience extreme distress. It is important not only to accurately diagnose the condition, but also to have an indication of the level of severity.

Our laboratory offers a simple process to gather the necessary data. After ingesting a sugar substrate, the patient provides breath samples every 30 minutes over a 3-hour time period. Samples are then mailed to the laboratory. Analysis of the samples yields data on hydrogen and/or methane production during the digestive process. Test data provides key indicators of the existence/extent of lactose intolerance/malabsorption.

How to prepare for the Lactose Intolerance Breath Testing?

There is a 24-hour preparation period before taking the test; the first 12 hours require a specific diet, and the last 12 hours require a complete fasting period; however, you may brush your teeth.

How to tell if you are lactose intolerant

If you have nausea, stomach cramps, gas, bloating, or diarrhea within 15 minutes to several hours after eating or drinking dairy foods, you may want to contact your doctor to determine if you have lactose intolerance.

Lactose levels in foods:

Dairy product

Lactose Content

Yogurt, plain, low-fat, 240mL


Milk, reduced fat, 240mL


Swiss cheese, 28g


Ice cream, 120mL


Cottage cheese, 120mL



How the Lactose Intolerance Breath Testing program works

  • The test is performed, in the physician's office or the patient's home
  • Breath samples are returned to Commonwealth Laboratories LLC in the postage paid box.
  • The analytical results are faxed to the physician's office


Download Test Specifications and Instruction Manual

Questions? Contact us!