Presented in this video are methods of localization of pathology within the colon. Methods described include the length of the instrument within the patient, a description of specific internal anatomy, the use of transillumination of light through the abdominal wall, and radiographic documentation using fluoroscopy or flat plates. Special techniques demonstrated include biopsy, polypectomy, and electrocoagulation, as well as injection techniques to document the location of pathology. A description of the newest endoscopic modalities, digital imaging and image management systems for storing and retrieving images is discussed and presented.