This chapter focuses on training to recognize and manage immediate complications of therapeutic endoscopy. Patients being considered for therapeutic endoscopy need to be assessed pre-procedure for risks that can be anticipated, and then steps can be taken to minimize or mitigate those risks. Issues to be addressed pre-procedure include a number of factors related to the cardiopulmonary risk of sedation, analgesia, or anesthesia; and risks related to the specific procedure such as bleeding for polypectomy, endoscopic mucosal resection, endoscopic submucosal dissection, peroral endoscopic myotomy, or sphincterotomy; or pancreatic risks related to endoscopic retrograde cholangiopancreatography. Perforation during colonoscopy can occur for a variety of reasons, including barotrauma, direct bowing, and force against the colon wall, or as a result of therapeutic procedures. Management of perforation begins with immediate recognition, and early recognition and prompt intervention may decrease patient morbidity and mortality.