Hydrogen Breath Tests for Lactose Intolerance and Bacterial Overgrowth

What is a hydrogen (glucose/lactose/lactulose) breath test?

The glucose and lactulose hydrogen breath tests are done to determine if there are excessive bacteria in the small bowel. Lactulose testing also may be used to determine the time it takes the sugar to move through the small bowel. The lactose hydrogen breath test is used to determine if the patient has lactose intolerance. The most common problems studied with the lactose test are: bloating and gas, abdominal pain, diarrhea or constipation.

How should you prepare for a hydrogen breath test?

Two Weeks Before the Test

  • If you are a diabetic, please talk to your doctor or call the endoscopy triage nurse at 617-525-6814 about how to take your medication in order to prevent low blood sugar.
  • No colonoscopy for two weeks prior to your appointment. If you have had a colonoscopy within 14 days prior to your appointment please call to reschedule your test.

One Week Before the Test

  • No antibiotics or probiotics for one week. If you have taken antibiotics or probiotics within 7 days of your appointment please call to reschedule your test.

The Day Before the Test

  • Do not eat the following foods: grain products, fruits and fruit juices, vegetable, nuts, seeds, beans, dairy products (except eggs), meat, pasta, corn, or corn products. Some suggestions for meals include: baked or broiled chicken or turkey (salt and pepper only), baked or broiled fish (salt and pepper only), plain steamed white rice, eggs, clear chicken or beef broth.
  • Do not eat or drink foods with fructose, corn syrup, sorbitol or alcohol sugars commonly found in chewing gum and candy. Regular sugar, Sweet & Low, Equal, and Stevia are OK to eat.
  • The evening meal should be light. Avoid rich heavy food.
  • NOTHING TO EAT OR DRINK, EXCEPT WATER, FOR 12 HOURS BEFORE YOUR TEST.

The Morning of the Test

  • NOTHING TO EAT OR DRINK, EXCEPT WATER, FOR 12 HOURS BEFORE YOUR TEST.
  • You may brush your teeth and take your normal medications the day of your test.
  • No vigorous exercise for one hour before or during your test.
  • No smoking, including second hand smoke for at least 1 hour before or during your test

Hydrogen Breath Test - Printable Instructions

What should you expect on the day of the hydrogen breath test?

The technician will ask you to drink a sugar solution. They will then ask you to exhale into a special breathing tube. Up to three separate breathing attempts may be needed.

Contact Us

To request an appointment or more information about the procedure, please contact us at (617) 732-7426.

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