Gastrointestinal (GI) tract bleeding of unknown origin is a vexing clinical problem. In this review, we discuss those causes of GI tract hemorrhage most likely to escape detection by conventional diagnostic modalities and explain how newer techniques of flexible fiberoptic endoscopy, radionuclide scanning, and angiography may be used to establish a diagnosis. We reviewed the literature on the role of exploratory surgery in the diagnosis of occult GI tract bleeding and conclude that its diagnostic yield is small and its value limited. Finally, we present a diagnostic approach to the patient with GI tract bleeding of unknown origin.
(Arch Intern Med 1982;142:236-240)