Test Overview

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.

Three tests are used to detect H. pylori:

• 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.
• Stool antigen test. A stool antigen test checks to see if substances that trigger the immune system to fight an H. pylori infection ( H. pylori antigens) are present in your feces (stool). Stool antigen testing may be done to help support a diagnosis of H. pylori infection or to find out 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. To learn more, see the topic Upper Gastrointestinal Endoscopy.

Why It Is 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 To Prepare

Stool antigen test

Medicines may change the results of this test. Be sure to tell your doctor about all the prescription and non-prescription medicines you take. Your doctor may recommend that you stop taking some of your medicines.

• Do not take antibiotics or medicines containing bismuth (such as Pepto-Bismol) for 1 month before the test.
• Do not take proton pump inhibitors (such as Nexium or Prilosec) for 2 weeks before the test.

Stomach biopsy or urea breath test

You will be asked to not eat or drink anything for a certain amount of time before having a breath test or a stomach biopsy. Follow your doctor's instructions about how long you need to avoid eating and drinking before the test.

Many medicines may change the results of this test. Be sure to tell your doctor about all the prescription and non-prescription medicines you take. Your doctor may recommend that you stop taking some of your medicines.

• Do not take antibiotics or 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 or cimetidine, for 24 hours before the test.

How It Is 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.

How It Feels

Urea breath test

This test usually doesn't cause any pain or discomfort.

Stool antigen test

This test usually doesn't cause any pain or discomfort.

If your doctor collects the sample during a rectal exam, you may feel some pressure or discomfort as the cotton swab is inserted into your rectum.

Stomach biopsy

You may notice a brief, sharp pain when the intravenous (I.V.) needle is placed in a vein in your arm. The local anesthetic sprayed into your throat usually tastes slightly bitter and will make your tongue and throat feel numb and swollen. Some people report that they feel as if they cannot breathe at times because of the tube in their throat, but this is a false sensation caused by the anesthetic. There is always plenty of breathing space around the tube in your mouth and throat. Remember to relax and take slow, deep breaths.

You may have some gagging, nausea, bloating, or mild abdominal cramping as the tube is moved. Even though you won't be able to talk during the procedure because you have a tube in your throat, you can still communicate. If the discomfort is severe, alert your doctor with an agreed-upon signal or a tap on the arm.

The I.V. medicines will make you feel sleepy. Other side effects—such as heavy eyelids, trouble speaking, a dry mouth, or blurred vision—may last for several hours after the test. The medicines may also cause you not to remember much of what happens during the test.

Risks

Urea breath test

There are no known risks or complications with a urea breath test. If radioactive carbon is used, the amount of radioactivity exposure is extremely small—less than you normally get from being outside during the day.

Stool antigen test

There are no risks or complications with a stool sample. But if you don't wash your hands well after collecting the sample, you may spread germs.

Stomach biopsy

There is a slight risk of puncturing the wall of the esophagus, stomach, or duodenum during an endoscopy to collect stomach biopsy samples. The biopsy may also cause some bleeding at the site where the samples are collected. But the bleeding usually stops without treatment.

Results

Results from the urea breath test or a stool antigen test are usually available within a few hours. Results from biopsy samples obtained by endoscopy are usually available within 48 hours. Results from a biopsy sample that is cultured can take up to 10 days.