The Third Eye Retroscope is a device that can be used with a colonoscope to improve the ability of a physician to see areas of the colon that may be hidden from the view of the colonoscope.

Previous studies have shown that physicians are able to detect additional polyps when they use the device along with the colonoscope. The purpose of this study is to determine whether physicians can detect greater numbers of additional polyps as they gain in experience with the device.

Purpose: This study is intended to determine characteristics of the "learning curve" for use of the Third Eye Retroscope during colonoscopy, both in terms of efficacy for detection of abnormalities in the colon and time-efficiency for endoscopists

Device Description: The Third Eye Retroscope is an auxiliary imaging device that is designed to allow visualization of "hidden areas" during colonoscopy by providing an additional, retrograde view that complements the forward view of the colonoscope.

After a standard colonoscope has been advanced to the cecum, the Third Eye Retroscope is inserted through the instrument channel of the colonoscope. As it emerges from the distal tip of the colonoscope, the Third Eye Retroscope automatically bends 180 degrees to form a "J" shape. Its sensor then provides a continuous retrograde view of the colon throughout the process of withdrawal of the colonoscope.

The retrograde view assists the endoscopist in visualizing the proximal aspect of haustral folds and rectal valves, as well as the areas behind flexures and the ileocecal valve. With this additional point-of-view, the endoscopist may be able to detect lesions that can be missed by the forward-viewing colonoscope.

Study Design: Patients who are scheduled for colonoscopy will be recruited to the study and examined with the Third Eye Retroscope in conjunction with a standard colonoscope. For each polyp that is found, the endoscopist will indicate whether it could be seen with the colonoscope, or if it could be found with the colonoscope only because it was first detected with the Third Eye.

Each investigator will perform colonoscopies on 20 patients, who will be segmented into four quartiles according to the order of their procedures. Mean results for the quartiles will be compared in order to evaluate the learning curve for Third Eye colonoscopy.

Inclusion Criteria:

1. The patient is undergoing colonoscopy for screening, for surveillance in follow-up of previous polypectomy or for diagnostic workup;
2. The patient must understand and provide written consent for the procedure.

Exclusion Criteria:

1. Patients with a history of colonic resection;
2. Patients with inflammatory bowel disease;
3. Patients with a personal history of polyposis syndrome;
4. Patients with suspected chronic stricture potentially precluding complete colonoscopy;
5. Patients with diverticulitis or toxic megacolon;
6. Patients with a history of radiation therapy to abdomen or pelvis.
7. Patients who are currently enrolled in another clinical investigation in which the intervention might compromise the safety of the patient's participation in this study.

Per-protocol population of patients for whom the colonoscopy procedure was completed using the Third Eye Retroscope, not including the 30 who were withdrawn due to reasons stated above.

48-hour telephone follow-up to assess for post-procedural complications

No randomization or blinding and no separate control group. Determinations regarding adequacy of bowel cleansing and whether each polyp could have been detected with the colonoscope alone involved a judgement by the endoscopist.

Open Label