American College of Gastroenterology
Advancing Gastroenterology, Improving Patient Care

H. pylori


  • What is H. pylori and how common is it?

    H. pylori infection occurs when a type of bacteria called H. pylori infects a person's stomach. It is a common infection that is prevalent all over the world. Generally, it does not cause any symptoms or problems. However, in some people, it can lead to:

    1. Open sores or ulcers in the stomach or small bowel lining.
    2. Stomach cancer


  • What symptoms occur with H. pylori infection?

    Most people with this infection have no symptoms. However, some people get ulcers and have upper belly pain, bloating, nausea, vomiting or gassiness. Some people feel full after a small meal, others feel less hungry. When ulcers bleed a person may feel tired, have dark black tarry stools or bloody vomit.


Risk Factors


  • How is H. pylori diagnosed?
    1. Blood test: Checks for the antibody to H. pylori.
    2. Breath test: Measures a chemical in the breath that is present if H. pylori is in the stomach.
    3. Stool test: Checks for bacteria in the stool.
    4. Biopsy: A piece taken from the stomach lining during an endoscopy is checked under a microscope to see the bacteria.


  • How is H. pylori treated?

    Treatment for this germ always takes more than one medicine to kill it. Most people will need at least 3-4 medicines taken for about 10 to 15 days to cure this infection. It is important to take all these medicines until they are gone. Side effects of these medicines can be stomach upset, nausea, or diarrhea. These typically go away when the medicine is done. If the first treatment does not work, a different treatment will be given. When on treatment, it is essential to follow your doctor's instructions. Take medicines as recommended, and let your doctor or nurse know if you have any side effects or problems with your medications. Follow-up tests after treatment include a breath test, a test to check a sample of bowel movement for infection, and upper endoscopy with biopsy.

    Also, people diagnosed with ulcers are tested for H. pylori infection. The treatment of this condition can help ulcers heal and prevent ulcers from coming back. Treatment for H. pylori also prevents the long-term risk of cancer.

Author(s) and Publication Date(s)

Rohit Singhania, MD, SM, FACG, UMMS - Baystate Regional Campus, Springfield, MA – Published August 2021.

Victoria M. B. Howard, PA, University of Rochester, Rochester, NY – Updated April 2024.

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