Several tests and procedures are used to determine whether you have Helicobacter pylori (H. pylori) infection. Testing is important for detection of Helicobacter pylori (H. pylori). Repeat testing after treatment is important to be sure H. pylori is gone. Tests may be done using a stool sample, through a breath test and by an upper endoscopy exam.

Stool tests

  • Stool antigen test. This is the most common stool test to detect H. pylori. The test looks for proteins (antigens) associated with H. pylori infection in the stool.
  • Stool PCR test. A lab test called a stool polymerase chain reaction (PCR) test can detect H. pylori infection in stool. The test can also identify mutations that may be resistant to antibiotics used to treat H. pylori. However, this test is more expensive than a stool antigen test and may not be available at all medical centers.

Breath test

During a breath test — called a urea breath test — you swallow a pill, liquid or pudding that contains tagged carbon molecules. If you have H. pylori infection, carbon is released when the solution comes in contact with H. pylori in your stomach.

Because your body absorbs the carbon, it is released when you breathe out. To measure the release of carbon, you blow into a bag. A special device detects the carbon molecules. This test can be used for adults and for children over 6 years old who are able to cooperate with the test.

Scope test

A health care provider may conduct a scope test, known as an upper endoscopy exam. Your provider may perform this test to investigate symptoms that may be caused by conditions such as a peptic ulcer or gastritis that may be due to H. pylori.

For this exam, you'll be given medication to help you relax. During the exam, your health care provider threads a long, flexible tube with a tiny camera (endoscope) attached down your throat and esophagus and into your stomach and the first part of the intestine (duodenum). This instrument allows your provider to view any problems in your upper digestive tract. Your provider may also take tissue samples (biopsy). These samples are examined for H. pylori infection.

Because this test is more invasive than a breath or stool test, it's typically done to diagnose other digestive problems along with H. pylori infection. Health care providers may use this test for additional testing and to look for other digestive conditions. They may also use this test to determine exactly which antibiotic may be best to treat H. pylori infection, especially if the first antibiotics tried didn't get rid of the infection.

This test may be repeated after treatment, depending on what is found at the first endoscopy or if symptoms continue after H. pylori infection treatment.

Testing considerations

Antibiotics can interfere with the accuracy of testing. In general, retesting is done only after antibiotics have been stopped for four weeks, if possible.

Acid-suppressing drugs known as proton pump inhibitors (PPIs) and bismuth subsalicylate (Pepto-Bismol) can also interfere with the accuracy of these tests. It's possible acid-suppressing drugs known as histamine (H-2) blockers may also interfere with the accuracy of these tests. Depending on what medications you're taking, you'll need to stop taking them, if possible, for up to two weeks before the test. Your health care provider will give you specific instructions about your medications.

The same tests used for diagnosis can be used to tell if H. pylori infection is gone. If you were previously diagnosed with H. pylori infection, you'll generally wait at least four weeks after you complete your antibiotic treatment to repeat these tests.


H. pylori infections are usually treated with at least two different antibiotics at once. This helps prevent the bacteria from developing a resistance to one particular antibiotic.

Treatment may also include medications to help your stomach heal, including:

  • Proton pump inhibitors (PPIs). These drugs stop acid from being produced in the stomach. Some examples of proton pump inhibitors (PPIs) are omeprazole (Prilosec), esomeprazole (Nexium), lansoprazole (Prevacid) and pantoprazole (Protonix).
  • Bismuth subsalicylate. More commonly known by the brand name Pepto-Bismol, this drug works by coating the ulcer and protecting it from stomach acid.
  • Histamine (H-2) blockers. These medications block a substance called histamine, which triggers acid production. One example is cimetidine (Tagamet HB). histamine (H-2) blockers are only prescribed for H. pylori infection if PPIs can't be used.

Repeat testing for H. pylori at least four weeks after your treatment is recommended. If the tests show the treatment didn't get rid of the infection, you may need more treatment with a different combination of antibiotics.

Clinical trials

Explore Mayo Clinic studies testing new treatments, interventions and tests as a means to prevent, detect, treat or manage this condition.

Preparing for your appointment

See your health care provider if you have signs or symptoms that indicate a complication of H. pylori infection. Your provider may test and treat you for H. pylori infection, or refer you to a specialist who treats diseases of the digestive system (gastroenterologist).

Here's some information to help you get ready for your appointment, and what to expect.

What you can do

At the time you make the appointment, ask if there's anything you need to do in advance, such as restrict your diet.

Also, preparing a list of questions to ask may help you make the most of your time with your health care provider. Questions to ask may include:

  • How did H. pylori infection cause the complications I'm experiencing?
  • Can H. pylori cause other complications?
  • What kinds of tests do I need?
  • Do these tests require any special preparation?
  • What treatments are available?
  • What treatments do you recommend?
  • How will I know if the treatment worked?

Ask any additional questions that occur to you during your appointment.

What to expect from your doctor

Your health care provider is likely to ask you a number of questions, such as:

  • Have your symptoms been continuous or occasional?
  • How severe are your symptoms?
  • When did your symptoms begin?
  • Does anything make them better or worse?
  • Have your parents or siblings ever experienced similar problems?
  • What medications or supplements do you take regularly?
  • Do you take any over-the-counter pain relievers such as aspirin, ibuprofen (Advil, Motrin IB, others) or naproxen sodium (Aleve)?

Being ready to provide information and answer questions may allow more time to cover other points you want to discuss.

May 05, 2022

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