Colonoscopy is a diagnostic procedure to evaluate the inner lining of the colon and rectum. It is performed with a colonoscope - a long, flexible lighted tube with a camera. The colonoscope is inserted into the anus and passed through the rectum and colon. It allows your doctor to view the entire colon and rectum as well as the lower part of the small intestine. Colonoscopy is recommended for people aged 50 and above with a normal risk of colorectal cancer. The test helps to diagnose tumors, ulcers, polyps and areas of inflammation or bleeding.