Severe lower intestinal bleeding: Diagnosis and treatment

The diagnostic approach and management of severe lower intestinal bleeding have changed dramatically during the past decade. Selective angiography, flexible fibre-optic endoscopy, and more sophisticated radioisotope scanners have made possible the accurate identification of the site and cause of the bleeding, and have provided new therapeutic modalities for its temporary, or even permanent, control. Vascular lesions of the colon, previously thought to be rare, have been recognized as a common cause of lower intestinal bleeding in the elderly, and diverticular bleeding from the right half of the colon has been documented to be more frequent than from the left half. Intravenous or selective arterial infusions of vasoconstrictors, transcatheter embolization and colonoscopic polypectomy and electrofulguration have all been added to our therapeutic armamentarium. These many advances dictate a reassessment of old tenets. The prominent roles of exploratory laparotomy in children and blind subtotal colectomy in the elderly have diminished, as has the need for emergency operation. In this chapter we will review changing concepts of the nature of severe lower intestinal bleeding and present our approach to its diagnosis and management. This approach reflects our new understanding of the causes of this type of bleeding and embodies the new techniques for its identification and treatment.