Use of heparin in the investigation of obscure gastrointestinal bleeding.

OBJECTIVE: To determine if the administration of heparin improves the predictive value of angiography in the investigation of obscure gastrointestinal (GI) bleeding. METHODS: 18 patients with a history of chronic GI bleeding were investigated with angiography. For 6 patients, the cause of GI bleeding was established with angiography; the 12 patients who had negative results were given heparin for 24 h and were reassessed with angiography.