What Is H. pylori Infection?
For years scientists and doctors thought that stomach and intestinal ulcers were caused by stress, eating spicy foods, or drinking too much alcohol. But in 1982 two Australian doctors, Barry Marshall and Robin Warren, discovered that H. pylori, a bacterium that lives in the lining of the stomach, can cause what is known as peptic ulcer disease. H. pylori infection is found in about 90 percent of people with ulcers in the duodenum (do-uh-DEE-num), the upper part of the small intestine. H. pylori infection is also responsible for most gastric (GAS-trik), or stomach, ulcers. Although H. pylori bacteria are responsible for most peptic ulcers, ulcers also can be caused by regularly taking certain medications, such as aspirin or ibuprofen; long-term smoking or alcohol use; infection with certain viruses; and, rarely, tumors in the pancreas or small intestine that lead to overproduction of stomach acid. H. pylori infection also can cause gastritis (gah-STRY-tis), or inflammation of the lining
