Diagnosis of gastrointestinal bleeding in adults.

The clinical evaluation of gastrointestinal bleeding depends on the hemodynamic status of the patient and the suspected source of the bleeding. Patients presenting with upper gastrointestinal or massive lower gastrointestinal bleeding, postural hypotension, or hemodynamic instability require inpatient stabilization and evaluation. The diagnostic tool of choice for all cases of upper gastrointestinal bleeding is esophagogastroduodenoscopy; for acute lower gastrointestinal bleeding, it is colonoscopy, or arteriography if the bleeding is too brisk. When bleeding cannot be identified and controlled, intraoperative enteroscopy or arteriography may help localize the bleeding source, facilitating segmental resection of the bowel. If no upper gastrointestinal or large bowel source of bleeding is identified, the small bowel can be investigated using a barium-contrast upper gastrointestinal series with small bowel follow-through, enteroclysis, push enteroscopy, technetium-99m-tagged red blood cell scan, arteriography, or a Meckel's scan. These tests may be used alone or in combination.