Abstract
The presence of a carcinoid tumor as a cause of lower gastrointestinal bleeding is rare and to our knowledge only 16 detailed cases have been reported in the medical literature to date (1– 3). We report an unusual case in which carcinoid tumor was the cause of lower gastrointestinal bleeding and in which upper endoscopy, colonoscopy, and mesenteric arteriography failed to detect the source of bleeding. A diagnosis of lower gastrointestinal bleeding secondary to carcinoid tumor was made following in vitro scintigraphy with technetium-99m labeled red blood cells and enterocolysis.