In this episode, we review the principles and practice of endoscopy in colorectal surgery. Topics include indications for diagnostic and therapeutic endoscopy, scope design and function, and the essential steps for safe technique. We cover screening colonoscopy, polypectomy, management of bleeding, and evaluation of inflammatory bowel disease, as well as the role of endoscopy in cancer detection and surveillance. Clinical pearls and common pitfalls are highlighted to guide fellows and practicing surgeons in applying endoscopy effectively and safely in daily practice.