The role of the radiologist in acute gastrointestinal bleeding.

Angiography is valuable in the diagnostic and therapeutic management of the patient with acute gastrointestinal bleeding. It should be preceded by endoscopy in acute upper gastrointestinal bleeding, but in acute lower gastrointestinal bleeding, angiography is firmly established as the primary diagnostic modality. Although angiography is less useful in chronic gastrointestinal bleeding, it may show the underlying pathologic lesion. Vasonconstrictive and embolic therapeutic angiographic procedures are particularly valuable in the patient with multiple system disease.