Approximately half the global population is infected with H. pylori. Most have no symptoms, and do not require treatment. However, a minority of these people develop gastritis, and a small fraction develop gastric ulcers or gastric cancer.
The standard procedure to diagnose H. pylori involves endoscopy with biopsy. Current guidelines still recommend this for patients with alarm symptoms such as GI bleeding or sudden weight loss, or for patients over 55. However, younger patients who do not have alarm symptoms may benefit from non-invasive tests, such as a fecal antigen test. These tests can also verify that H. pylori infection has been eradicated after treatment.