The stomach is the organ of the digestive system in which food travels from the esophagus and is further broken down before its nutrients are absorbed in the small intestine. It produces acid and various enzymes that break down food into simple substances. The inside wall of the stomach is protected from the acid and enzymes by a mucous lining.

Ulcers are caused when there is an imbalance between the digestive juices produced by the stomach and the various factors that protect the lining of the stomach. Symptoms of ulcers may include bleeding. On rare occasions, an ulcer may completely erode the stomach wall.

A major cause of stomach ulcers is the bacteria called Helicobacter pylori. Treatment regimens for ulcers caused this bacterium usually include medications to suppress the stomach acid as well as antibiotics to eradicate the infection.