Recent data have confirmed that non-steroidal anti-inflammatory drugs can cause serious damage to the gastrointestinal tract involving localizations other than the well-known gastroduodenal complications. Perforation and hemorrhage of the small bowel have been reported as well as ulcerations, stenoses and diaphragm disease. The same type of lesions can occur in the large bowel in addition to ischemia and collagen colitis. Diverticular diseases of the colon can be complicated by use of non-steroidal anti-inflammatory drugs which may also trigger flare-ups of inflammatory diseases. Use in suppository form can complicate rectitis and rectal stenosis. Non-steroidal anti-inflammatory drugs apparently increase intestinal permeability by inhibiting the cyto-protective effect of prostaglandins. The exact frequency of such complications remains to be determined, but prolonged treatment in elderly subjects appears to increase risk. Current data have not shown greater or lesser toxicity for any specific drug. Non-steroidal anti-inflammatory drugs should be entertained as the cause of intestinal disorders in patients under long-term treatment.