MODEL RELEASED. Colonoscopy procedure. Surgeons using a colonoscope, a type of flexible endoscope, to examine the colon of a patient. A colonoscope contains a fibre-optic cable which allows the surgeon to examine the interior of the large intestine. It is usually inserted through the rectum, as seen here. The device may also be fitted with forceps and cutting instruments to retrieve tissue samples for biopsy examination, or to remove polyps. Crohn's disease, ulcers, and cancer of the bowel may be diagnosed in this way. The study and treatment of the colon, rectum and anus is collectively known as proctology.