TY - CHAP M1 - Book, Section TI - Chapter 11. Gastrointestinal Bleeding A1 - Balakrishnan, Anita A1 - Tavakkoli, Ali A1 - Ashley, Stanley W. A2 - Zinner, Michael J. A2 - Ashley, Stanley W. Y1 - 2013 N1 - T2 - Maingot's Abdominal Operations, 12e AB - Acute gastrointestinal (GI) hemorrhage is a significant cause of morbidity and mortality in the emergency setting. The source of GI bleeding can range from the esophagus through to the colon and is classified into upper or lower GI bleeding depending on the site of bleeding relative to the ligament of Treitz. Upper GI hemorrhage occurs from sites proximal to the ligament of Treitz frequently due to peptic ulcer disease and variceal hemorrhage and accounts for more than 80% of acute bleeding.1 The majority of lower GI bleeding originates from the colon from pathologies such as diverticular disease and angiodysplasias. The small intestine is the site of hemorrhage in fewer than 5% of patients.1 Hemorrhage persisting or recurring after negative endoscopy is termed obscure bleeding. Occasionally patients present with occult bleeding, where there are no signs of overt bleeding, but the presenting symptoms are due to chronic blood loss and anemia. In all cases, thorough investigation to localize the source of bleeding allows rapid and often definitive management. SN - PB - The McGraw-Hill Companies CY - New York, NY Y2 - 2024/03/28 UR - accesssurgery.mhmedical.com/content.aspx?aid=57007789 ER -