It is the procedure of visualizing all of the large intestine and segments of small intestine in neighbourhood of large intestine with a thin, flexible pipe that has a camera on its tip. Sigmoidoscopy is the name of evaluation of the large intestine segment that is close to the anus. Intestines must be cleaned by administration of purgative medications. It is the most reliable method for the diagnosis of colon (large intestine) cancer. Additionally it protects patients with providing identification and removal of pre-cancerous lesions such as polyps.
It is recommended for everyone after 50 years of age for the prevention of colon cancer. For those who have close relatives with colon cancer, colonoscopy must be performed 10 years before the youngest cancer onset age of the family. Majority of colon cancers develop over benign tumors called polyp. Colonoscopy done at appropriate time ensures the identification of polyps before cancer development and removal of them (polypectomy). Therefore it protects the patients from both cancer and surgery. For those who had polyps removed from large intestine, follow up colonoscopies with 1 to 3 years intervals according to the specification of polyp is required. Colonoscopy is also used for the diagnosis and follows up of non-cancer diseases such as Ulcerative Colitis, Chrohn Disease. Colonoscopy may save patients form surgery by providing diagnosis and treatment of large intestine bleedings.