Urokinase in gastrointestinal tract bleeding.

Selective urokinase infusion into the superior mesenteric artery allowed the accurate determination of the site of small bowel bleeding in a patient with recurrent lower gastrointestinal bleeding who bled despite resective surgery and who had negative findings on four angiograms. Fibrinolytic agents are useful in rare cases in which the need for successful and accurate diagnosis outweighs the risks of reactivating the bleeding.