Provocative red blood cell scintiscan in occult chronic gastrointestinal hemorrhage.

A patient with a chronic occult gastrointestinal bleeding site is described. Because an extensive examination failed to locate the site of bleeding, a heparin infusion was used in conjunction with a conventional Tc-99m labeled red cell bleeding study. A mid-jejunal ulcer was safely localized before elective surgery. A protocol for a heparin provocative bleeding study is proposed.