Colonoscopy Beverly Hills By Dr. Peyton Berookim Top GI in California|Nashville News : If you are age 50 or older, medical guidelines state that you should be get a colonoscopy at least once every 10 years. In case you’re unfamiliar with the text, a colonoscopy is the medical exam used to determine whether you have abnormal tissue, ulcers, polyps or adenomas in your colon that may become, or are already, cancerous. Colonoscopies are performed by gastroenterologists like Dr. Peyton Berookim, a double-board certified GI doctor whose practice is based in Beverly Hills.