Significance of a positive test for occult blood in stools of patients taking anti-inflammatory drugs.

Physicians often attribute positive Hemoccult card tests in patients taking anti-inflammatory drugs to the irritant effects of these drugs on the gastrointestinal (GI) tract mucosa. A study of 167 patients attending a rheumatic disease clinic showed that 145 (86.8%) were taking an anti-inflammatory drug, but only eight of these patients (4.8%) had positive tests for occult blood. An investigation revealed that three patients had neoplasms, two had inflammatory bowel disease, one had a bleeding internal hemorrhoid, one had a bleeding diverticulum, and one had peptic ulcer disease. Anti-inflammatory agents appear to have caused or contributed to the GI tract bleeding only in the patient with peptic ulcer disease. The study shows that the Hemoccult card test is usually not positive in patients receiving anti-inflammatory medications. Accordingly, physicians should not attribute a positive Hemoccult card test to these drugs until other appropriate studies have ruled out the existence of underlying GI tract lesions.