Vascular disorders of the small bowel.

Approximately 5% of all patients with gastrointestinal hemorrhage, and up to 38% of subjects with iron deficiency anemia without overt gastrointestinal bleeding, do not have a bleeding site identified after routine evaluation by esophagogastroduodenoscopy and colonoscopy. The source of bleeding in these subjects is often the small intestine. Most vascular lesions of the small bowel present as chronic gastrointestinal bleeding, which may severe in some cases. Depending on the underlying disease, other systemic signs and symptoms may be present. The diagnosis and often therapy are heavily dependent upon endoscopic techniques, and in some cases nonendoscopic methods.