Endoscopy in patients with upper GI bleeding is effective in diagnosing and treating most causes of upper GI bleeding. Endoscopy is associated with a reduction in blood transfusion requirements and length of stay in the intensive care unit and hospital. Early endoscopy (within 24 hours of admission to the hospital) has a greater impact than later endoscopy on length of hospital stay and requirement for blood transfusion. No single method of endoscopic therapy is superior to another. Routine second-look endoscopy (performed 16 hours to 24 hours after first endoscopy) in a stable patient is not recommended. A second attempt at endoscopic therapy is generally recommended in cases of re-bleeding.