Dr. Gralnek is considered an authority on GI bleeding, and he has invited experts in their respective fields to contribute to this issue. The content is divided up between Acute Non-Variceal Upper GI Hemorrhage and Acute Lower Gastrointestinal Hemorrhage. Articles are devoted to the follow topics: Initial assessment, risk stratification and early management; Endotherapy of peptic ulcer bleeding; Endoscopic hemostasis of non-variceal, non-ulcer UGIH; Emerging endoscopic treatments for NVUGIH; The cutting edge: doppler ultrasound in guiding endoscopic hemostasis; The role of interventional radiology in NVUGIH; Managing antithrombotic agents in the setting of acute GI bleeding; Patient presentation, risk stratification and initial management; Colonoscopy: Diagnosis, timing and bowel preparation; The role of endoscopic hemostasis therapy; and Prevention of recurrent lower GI hemorrhage. Readers will come away with the most current clinical infomration on how to manage and prevent GI bleeding.