Urea Breath Test for Helicobacter Pylori (H. Pylori)

The urea breath test is one method used to diagnose the presence of the bacterium, helicobacter pylori (H. pylori) in the stomach. H. pylori can cause peptic ulcers by damaging the mucous coating that protects the stomach and duodenum.

What to Expect

For the test, patients swallow a capsule containing urea made from an isotope of carbon. (Isotopes of carbon can occur in minuscule amounts in nature, and can be measured with special testing machines.) If H. pylori is present in the stomach, the urea is broken up and turned into carbon dioxide. The carbon dioxide is absorbed across the lining of the stomach and into the blood. It then travels in the blood to the lungs where it is excreted in the breath. Samples of exhaled breath are collected, and the isotopic carbon in the exhaled carbon dioxide is measured.

How to Prepare

The test requires a fasting period of at least one hour prior to your test. This means that you consume no food or drink, only water, prior to the test. Patients should inform their physicians, prior to their test, if they are taking any medications. Typically, patients are instructed as follows:

  • Phenylketonuric patients should not take the test as the active ingredients is mixed with aspartame and contains phenylalanine.
  • Do not take proton pump inhibitors (Prilosed, Prevacid, Nexium, Protonix, Aciphex) within two weeks prior to the test.
  • Do not take antibiotics within weeks prior to the test.
  • Do not take bismuth preparations (Pepto Bismol, etc.) within two weeks prior to the test.
  • If you have received H. pylori treatment, you should not take this test for a minimum of four weeks following the end of your treatment. An earlier post-treatment assessment may give false negative results.
  • Prior to testing, you may take H2 antagonists (Tagamet, Zantac, Papcid, Axid) or Antacids (Tums, etc.).