Nonsteroidal anti-inflammatory drugs have become increasingly popular, with more than 90 million prescriptions being written annually. These drugs inhibit the intracellular cyclooxygenase enzyme system, thus blocking the production of various prostaglandin compounds. This, in turn, interferes with normal mucosal protective mechanisms, leading to local injury. Gastrointestinal complications of nonsteroidal anti-inflammatory drug use include ulcerations, hemorrhage, perforation, stricture formation, and the exacerbation of inflammatory bowel disease. Treatment involves stopping the drug if at all possible and then instituting more specific therapy depending on the anatomic area that has been injured.