Lower GI bleeding is bleeding beyond the ligament of Treitz.
Lower GI bleeding is defined by:
(1) exclusion of upper GI bleeding (absence of melena and hematemesis; normal esophagogastroduodenoscopy)
(2) demonstration of a source distal to the ligament of Treitz by tagged RBCs, colonoscopy, surgery, angiography, etc.
Severe lower GI bleeding - both of the following:
(1) gross rectal bleeding after leaving the ED (with initial resuscitation) indicative of ongoing bleeding or rebleeding
(2) at least one of the following:
(2a) systolic blood pressure < 100 mm Hg
(2b) heart rate > 100 beats per minute
(2c) transfusion of > 2 units of packed RBCs during the hospital stay
where:
• A drop in hemoglobin can probably be used as a surrogate for the blood transfusion, since 1 unit of blood will typically cause an increase in hemoglobin by 1 g/dL.
