Velayos et al defined severe lower gastrointestinal (GI) bleeding based on clinical criteria. The authors are from the University of California San Francisco and Arizona State University in Tempe, Arizona.


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



• 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.


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