How the Breath Test Works
The test is called a urea breath test, or UBT. You drink a small amount of liquid containing urea tagged with a non-radioactive carbon isotope (13C). If H. pylori is in your stomach, the bacteria break down the urea and release labelled carbon dioxide. You exhale that CO2 into a collection bag, and the lab measures how much of the labelled carbon shows up.
If the level is elevated, you have an active infection. If it isn't, you don't. The test is roughly 95% accurate when prep instructions are followed properly, which is the main reason this article exists.
When Doctors Order This Test
Your doctor will usually suggest the breath test if you've had ongoing upper-abdomen pain, persistent nausea, bloating that won't go away with antacids, or indigestion that keeps coming back. It's also the standard test if you've been diagnosed with a stomach ulcer and your doctor wants to know whether H. pylori is the cause.
You're at higher risk if you've had peptic ulcers in the past, if a close family member has tested positive, or if you grew up somewhere with high H. pylori prevalence (it spreads through shared food and water in childhood, not adult contact).
The same test is also used after treatment to confirm the bacteria are actually gone. Most doctors retest about a month after you finish antibiotics.
How to Prepare
Fast for at least 6 hours. Most labs ask for nothing to eat or drink (water is fine) from midnight the night before, since the test is usually done in the morning. Food in the stomach can dilute the urea solution and produce a false negative.
Stop PPIs two weeks before. This is the big one. Omeprazole, pantoprazole, esomeprazole, lansoprazole, and rabeprazole all suppress H. pylori temporarily, which makes the bacteria invisible to the test. If you can't tolerate two weeks off, talk to your doctor about switching to an H2 blocker like famotidine, which only needs to be stopped 24 to 48 hours beforehand.
Stop antibiotics and bismuth (Pepto-Bismol) for 4 weeks. Both kill H. pylori partially, so even if the infection is still there, the test won't see it.
Tell the lab and your doctor if you can't stop any of these medications. They'll either reschedule or pick a different test (such as a stool antigen test or biopsy through endoscopy).
The Day of the Test
Arrive on an empty stomach and bring your health card and requisition. Here's the order things happen in:
- Check in and confirm you've followed the fasting and medication rules.
- Breathe into a foil bag to give a baseline sample.
- Drink the test solution. It tastes a bit like flat lemon water; some people find it slightly chalky.
- Sit quietly for 15 to 30 minutes. No eating, drinking, smoking, or chewing gum during the wait.
- Breathe into a second bag.
Total time in the clinic is usually 30 to 45 minutes. The actual "test" part is just two exhales. Once you're done, you can eat, take your medications, and go about your day normally.
After the Test
Most people have no side effects. A small number of patients feel a bit of stomach unease from the urea solution. It passes within an hour. Results take 1 to 2 business days, sometimes longer, depending on where the samples are sent.
If the test is positive, your doctor will start you on triple or quadruple therapy: two antibiotics plus a PPI, sometimes with bismuth added, for 10 to 14 days. After you finish, you'll repeat the breath test about four weeks later to make sure the bacteria are gone.
If the test is negative and you're still having symptoms, the next steps depend on what's likely causing them. That might mean an upper endoscopy, a trial of acid-suppressing medication, or further investigation for things like reflux, gastritis, or gallbladder disease.
Practical Tips
- Mark the medication stop dates on your calendar the day you book the test. Two weeks for PPIs, four weeks for antibiotics and bismuth. It's easy to lose track.
- Schedule the test first thing in the morning so the overnight fast does the work for you.
- If you slip up (took a pantoprazole by habit, had toast 30 minutes before your appointment) tell the lab. They'll reschedule rather than run a test that won't be valid.
Testing & Treatment
The breath test is simple, but only if you've done the prep. Skipping a PPI for two weeks isn't fun, especially if you've been relying on it for symptom relief, but a negative result on a suppressed stomach isn't really a negative result. TeleTest offers testing (blood testing before treatment, and breath test post treatment) and treatment for H. pylori. If you've had persistent stomach symptoms for more than a few weeks, talk to your doctor about whether testing is the right next step.
Frequently Asked Questions (FAQ)
What if I accidentally ate something before the test?
Call the lab. If it's been less than a few hours since you ate, they'll almost certainly reschedule. Don't try to hide it; a falsely negative test is worse than waiting another week.
How long does it take to get results?
Usually 1 to 2 business days. Some smaller labs ship samples out and take up to a week.
Can I continue taking my medications?
Most regular medications are fine. The three you have to stop in advance are PPIs (2 weeks), antibiotics (4 weeks), and bismuth-containing products like Pepto-Bismol (4 weeks). If you can't stop any of these, ask about a stool antigen test as an alternative.
Will the test hurt?
No. You drink a liquid and breathe into a bag. There's no needle and no scope.
What if my test is positive?
Your doctor will prescribe a 10 to 14 day course of antibiotics combined with a PPI. Finish the entire course even if you feel better after a few days. About 4 weeks after treatment ends, you'll repeat the breath test to confirm the bacteria are gone.
Disclaimer: This blog post is intended for educational purposes only and should not be taken as medical advice. Always consult your healthcare provider for personal health concerns.