Scintigraphy with In-111-labeled red cells in intermittent gastrointestinal bleeding.

The site of active intermittent gastrointestinal (GI) bleeding could not be found in a patient until abdominal scintigrams with indium-111-labeled red cells suggested that the bleeding was in the ascending colon. Right hemicolectomy abolished the hemorrhages. The binding of In-111 to the red cell is such that vascular activity could be clearly seen over a 5-day period. Indium-111-labeled red cells might provide an excellent tracer to locate intermittent active GI bleeding.