Lower gastrointestinal bleeding (LGIB) is usually self-resolving and less severe than upper GI bleeding (UGIB). Consider UGIB if the patient is unstable or has upper GI risk factors like cirrhosis.
CT angiography (CTA) is the preferred imaging method for active lower GI bleeding, with high sensitivity and specificity. The accuracy of CTA decreases if the bleeding has already stopped.
Patients on anticoagulation with active bleeds should temporarily stop their anticoagulation. Unstable patients should have their anticoagulation reversed, if possible.
Aortoenteric fistula should always be considered in the differential diagnosis. Inquire about the patient's surgical history, specifically abdominal aortic aneurysm (AAA) repair, as it could be a life-threatening condition.
A rectal exam is important for the evaluation of anal fissures, hemorrhoids, anorectal mass, and stool exam.