Helicobacter pylori Tests
Helicobacter pylori tests are used to detect a Helicobacter pylori (H. pylori) infection in the stomach and upper part of the small intestine (duodenum). H. pylori can cause peptic ulcers. But most people with H. pylori in their digestive systems do not develop ulcers.
Four tests are used to detect H. pylori:
- Blood antibody test. A blood test checks to see whether your body has made antibodies to H. pylori bacteria. If you have antibodies to H. pylori in your blood, it means you either are currently infected or have been infected in the past.
- Urea breath test. A urea breath test checks to see if you have H. pylori bacteria in your stomach. This test can show if you have an H. pylori infection. It can also be used to see if treatment has worked to get rid of H. pylori. The breath test is not always available.
- Stool antigen test. A stool antigen test checks to see if substances that trigger the immune system to fight an H. pylori infection (H. pyloriantigens) are present in your feces (stool). Stool antigen testing may be done to help support a diagnosis of H. pylori infection or to determine whether treatment for an H. pylori infection has been successful.
- Stomach biopsy. A small sample (biopsy) is taken from the lining of your stomach and small intestine during an endoscopy. Several different tests may be done on the biopsy sample. For more information, see the medical test Upper Gastrointestinal Endoscopy.
Why It Is Done
A Helicobacter pylori (H. pylori) test is done to:
- Determine whether an infection with H. pylori bacteria may be causing an ulcer or irritation of the stomach lining (gastritis).
- Determine whether treatment for an H. pylori infection has been successful.
How To Prepare
Blood antibody test
You do not need to do anything before you have a blood antibody test.
Stool antigen test
Medicines may change the results of this test. Be sure to tell your doctor about all the prescription and nonprescription medicines you take. Your doctor may recommend that you stop taking some of your medicines.
- Do not take proton pump inhibitors (such as Prilosec or Nexium) for 2 weeks before the test.
- Do not take medicines containing bismuth (such as Pepto-Bismol) for 1 month before the test.
Stomach biopsy or urea breath test
Do not eat or drink for at least 6 hours before a breath test or a stomach biopsy.
Many medicines may change the results of this test. Be sure to tell your doctor about all the prescription and nonprescription medicines you take. Your doctor may recommend that you stop taking some of your medicines.
- Do not take antibiotics for 1 month before the test.
- Do not take medicines containing bismuth (such as Pepto-Bismol) for 1 month before the test.
- Do not take proton pump inhibitors for 2 weeks before the test.
- Do not take H2 blockers, such as Pepcid, Zantac, Axid, or Tagamet, for 24 hours before the test.
Talk to your doctor about any concerns you have
regarding the need for the test, its risks, how it will be done, or what the
results may mean. To help you understand the importance of this test, fill out
the
medical test information form
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WebMD Medical Reference from Healthwise

