Gastric and duodenal ulcers are defects in the lining of the stomach or duodenum that form when gastric acid overwhelms the normal protective mechanisms. Most ulcers are caused by the bacteria Helicobacter pylori or by aspirin and similar drugs, which impair the stomach's defenses against gastric acid. Some rare ulcers are caused by tumors that produce gastrin, a hormone that stimulates gastric acid secretion. The lifetime prevalence of ulcers in the United States is 6 to 10 percent. Affected persons often experience indigestion, and about 20 percent have a complication, such as bleeding. Ulcers can be cured with drugs that suppress gastric acid secretion or eradicate Helicobacter pylori.
LAWRENCE S. FRIEDMAN
Friedman, L. S. (1988). "Peptic Ulcer Disease, Gastritis, and Zollinger-Ellison Syndrome." In Harrison's Principles of Internal Medicine, 11th edition, eds. E. Braunweld, K. J. Isselbacher, R. G. Petersdorf, J. D. Wilson, J. B. Martin, and A. S. Fauci. New York: McGraw-Hill.
LAWRENCE S. FRIEDMAN, The Gale Group Inc., Macmillan Reference USA, New York,