What is it?

H. pylori tests are used to check for a Helicobacter pylori bacteria infection in the stomach and upper part of the small intestine. H. pylori can cause peptic ulcers. But most people with this type of bacteria in their digestive systems do not get ulcers.

Different tests may be used to check for an H. pylori infection.

• Urea breath test. It tests your breath to see if you have H. pylori bacteria in your stomach.
• Stool antigen test. This test looks for substances in your feces (stool) that trigger the immune system to fight an H. pylori infection. (These substances are called H. pylori antigens.)
• Stomach biopsy. A small sample (biopsy) is taken from the lining of your stomach and small intestine. The samples are checked for H. pylori.

Why is this test done?

H. pylori tests are done to:

• Find out if an infection with H. pylori bacteria may be causing an ulcer or irritation of the stomach lining (gastritis).
• Find out if treatment for the infection worked.

How do you prepare for the test?

Urea breath test, stool antigen test, or stomach biopsy

• Medicines you take may change the results of these tests. Be sure to tell your doctor about all the prescription and over-the-counter medicines you take. Your doctor may advise you to stop taking some of your medicines.

Urea breath test or stomach biopsy

• You will be asked to not eat or drink anything for a certain amount of time before your breath test or stomach biopsy. Follow your doctor's instructions about how long you need to avoid eating and drinking before the test. If you are going to have a stomach biopsy, your doctor will give you instructions on how to prepare.

How is the test done?

Urea breath test

A breath sample is collected when you blow into a balloon or blow bubbles into a bottle of liquid. The health professional will:

• Collect a sample of your breath before the test starts.
• Give you a capsule or some water to swallow that contains tagged or radioactive material.
• Collect more samples of your breath. The samples will be tested to see if they contain material formed when H. pylori comes into contact with the tagged or radioactive material.

Stool antigen test

For this test, you may be asked to collect the stool sample at home. To collect the sample, you need to:

• Pass stool into a dry container. Either solid or liquid stools can be collected. Be careful not to get urine or toilet tissue in with the stool sample.
• Replace the container cap. Label the container with your name, your doctor's name, and the date the sample was collected.
• Wash your hands well after you collect the sample.
• Take the sealed container to your doctor's office or to the lab as soon as you can.

Stomach biopsy

A procedure called endoscopy is used to collect samples of tissue from the stomach and the first part of the small intestine. The tissue samples are tested in a lab to see if they contain H. pylori.