This product is used to treat H. pylori infection in the stomach. H. pylori can cause stomach problems such as ulcers. Omeprazole is known as a proton pump inhibitor (PPI). It works by blocking acid production in the stomach. Decreasing excess stomach acid can help treat stomach problems and allow ulcers to heal. Amoxicillin and rifabutin are antibiotics used to treat a wide variety of bacterial infections (including H. pylori). Treating the infection helps to reduce the risk of stomach problems (such as ulcers). Amoxicillin is a penicillin-type antibiotic and rifabutin is a rifamycin antibiotic. They work by stopping the growth of bacteria. The antibiotics in this product treat only bacterial infections. Antibiotics do not work for viral infections (such as common cold, flu). Using any antibiotic when it is not needed can cause it to not work for future infections.