An endoscopy that is undertaken to the level of the mid transverse colon would be coded as a Colonoscopy. A colonoscopy is a test using a thin flexible tube called a colonoscope to look closer at the colon; by looking closely at the inner lining of the large intestine, being the rectum and colon, doctors are able to further identify ulcers, tumors, bleeding, and inflammation, which other tests would not be able to discover as accurately. Hope that helps.