Breath Testing

What is Breath testing?

Certain kinds of digestive issues can allow unabsorbed food to reach the colon.  When this happens, some of the bacteria in the colon produce increased amounts of hydrogen and methane.  This hydrogen then finds its way into our breath, and those increased levels can be tested.

Breath testing can also be used to diagnose infection with certain bacteria.

Why do you need this test?

High amounts of hydrogen and methane in the breath can indicate that some foods are not being properly digested. The breath test can help diagnose conditions such as:

  • Malabsorption of sugars such as fructose, sucrose and glucose
  • Lactose intolerance
  • Small intestinal bacterial overgrowth (SIBO)
  • Irritable bowel syndrome

All of these conditions can cause significant gastrointestinal symptoms, including bloating, nausea, heartburn, indigestion, upset stomach, and diarrhoea.  

Preparing for the test

  • We will give you specific instructions about how to prepare.
  • In the days prior to your test, you can take your regular prescription medications (no antibiotics or probiotics), however, on the day of the test, withhold your usual medications until completion of test. If you have diabetes, you may need to adjust your insulin dosage before the test. Make sure to tell us about any prescription medications.
  • You need to fast for 12 hours prior to the test.
  • It is okay to drink water before and during your test.
  • No smoking until the completion of your test.
  • A single test involves drinking a sugar solution and providing a breath sample every 30 minutes for three hours (glucose is two hours only).
  • Do not exercise, smoke, chew gum, brush your teeth or use mouthwash on the day of the test.

What is involved in this test?

Due to COVID-19, we are currently offering at-home kits for breath testing.  There are some occasions where the breath test appointment can be completed onsite at MGIU, please discuss this with staff.

Breath testing is risk-free and involves no discomfort.

You start your hydrogen / methane breath test by blowing into a bag or tube to get a baseline breath sample.  Then you will drink a solution containing different types of sugar.  After that, you will breathe into a bag or tube every 30 minutes while the solution is digested.

Breath tests are easy to do, but they can take two to three hours.

What do the results mean?

Your doctor will measure how much your hydrogen level changes after you drink the sugar solution.  If it increases significantly, you may require treatment or make changes to your diet to relieve symptoms.