A colonoscopy is an exam used to detect changes or abnormalities in the large intestine (colon) and rectum. During a colonoscopy, a long, flexible tube is inserted into the rectum. If necessary, polyps or other types of abnormal tissue can be removed through the scope during a colonoscopy. Tissue samples (biopsies) can be taken during a colonoscopy as well. Colonoscopy is needed in case of investigating intestinal signs and symptoms, screening of colon cancer, detect increased polyps. Colonoscopy is performed by Gynaecologist and Obstetrician and Gastro Surgeon.