[Effect of non-steroidal antirheumatic agents on the gastrointestinal tract: clinical aspects and pathophysiology].

The major gastrointestinal side effects of non-steroidal antiinflammatory drugs (NSAID) mainly occur in the stomach and duodenum. Acute mucosal lesions are almost always seen but only 50% of patients complain of upper abdominal discomfort. NSAIDs elevate the risk of ulcerations of the stomach or duodenum 4 to 5 fold. Side effects in the small bowel are due to elevated intestinal permeability which may lead to inflammatory reactions, chronic blood loss and iron deficiency. Ulceration, perforation and strictures of the small and large bowel may also occur in rare cases.