Hydrogen Breath Test (HBT)
What is a Hydrogen Breath Test?
This is a test for lactose intolerance. It measures breath samples for too much hydrogen. The body makes too much hydrogen when lactose is not broken down properly in the small intestine.
What can I expect from a Hydrogen Breath Test?
This test requires that you drink a solution of lactose, fructose, sucrose, or glucose in water. Lactose is the sugar found in milk and is normally broken down in the small bowel. Glucose is a sugar that will be broken down by bacteria if present in the small bowel with hydrogen as a by-product. Sucrose is a common sugar found in foods such as candy. After drinking the solution, you will be asked to breath into a plastic bag. Breath samples are obtained every 15 minutes for adults, and every 30 minutes for children. The breath sample will be analyzed for hydrogen content to determine if you are able to properly break down the lactose or sucrose, or if you have bacteria overgrowth. The test lasts approximately two hours and is performed in the Gastroenterology Physiology Laboratory of the Medical Procedures Unit.
How do I prepare for the test?
Please follow these instructions to ensure a successful test. YOU MUST BE OFF ANTIBIOTICS AND PEPTO BISMOL FOR TWO WEEKS . On the evening before your hydrogen breath test, you may have the usual amounts of meat and vegetables from dinnertime until midnight . Please have only small amounts of sugar and starch , such as bread, pasta and cakes. After midnight , have nothing to eat, drink or smoke until your examination is completed .
Can I take my medications before the test?
Do not take any medication, including over the counter medication, unless your physician or nurse has advised you otherwise. Other critical medication such as for your heart, blood pressure, breathing or seizures should be taken with sips of water only on the morning of the procedure unless instructed to do otherwise by your doctor.
If you are unable to keep your appointment please call the GI Physiology Lab in the MPU at (734) 936-9250, option 2.
U-M Health System Related Sites:
Department of Internal Medicine Division of Gastroenterology
Directions to the Medical Procedures Unit
Instructions for Patients with Diabetes Having Outpatient Tests (on insulin)
Instructions for Patients with Diabetes Having Outpatient Tests (no insulin)
Other Related Web Sites:
National Institute of Digestive Diseases - Lactose Intolerance
Your Digestive System and How it Works
Information provided by UMHS Medical Procedures Unit staff, May 2005
