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Hydrogen breath test (SIBO, lactose)
hydrogen breath test · SIBO breath test · lactose intolerance test · lactose breath test
You drink a sweet solution and blow into a device every 15 to 30 minutes. The gases in your breath show how your bowel digests sugars.
For bloating, pain, or diarrhea after meals. To check for too many bacteria in the small bowel, called SIBO, or for lactose intolerance.
⏱ Duration: usually 2 to 3 hours; results are given right away or in a few days
Be sure to tell your doctor
How to prepare
- Diet the day before. Usually for 24 hours: no beans, dairy, sweets, fruit, or flour foods. Most often allowed: rice, meat, fish, and eggs. The clinic will give you a list.
- Fasting. Usually 10 to 12 hours without food. Water is fine.
- In the morning. Do not smoke, chew gum, or drink coffee. Brush your teeth.
- Medicines. You are sometimes asked to skip some medicines before the test. Do not stop anything on your own. Ask your doctor.
What to bring
- Your referral
- A book or phone. There is a lot of waiting
- Water, if allowed
How it goes
- First, you breathe out into the device. This is your starting level
- You drink the sugar solution
- Every 15 to 30 minutes, you blow into the device again
- You sit quietly at the clinic the whole time
- You are told when the test is over
What you'll feel
- It does not hurt
- During the test, you may get bloating, rumbling, or loose stool. This is part of the answer
- The waiting can be tiring
Afterwards
- You can eat after the test
- Bloating usually passes within the day
- Your doctor will explain the result
Common questions
Can I drink water during the test?
Most often, a little plain water is fine. Check with the clinic.
Why can't I smoke?
Smoking changes your breath, and the result will be wrong.