Please select the eligibility criteria that correspond to the clinical trial below.
Title: Third Eye Retroscope Randomized Clinical Evaluation (The "TERRACE" Study)
Brief Summary: The Third Eye® Retroscope® is a device that can be inserted through the instrument channel of a standard colonoscope to provide an additional, retrograde (or backward) view that reveals areas behind folds and flexures in the colon, and might detect additional polyps that cannot be seen with the colonoscope alone.

Patients who participate as subjects in the study will undergo two complete colonoscopy procedures, a standard colonoscopy and a colonoscopy in which a Third Eye Retroscope is used along with the same colonoscope. Half of the patients will have the standard colonoscopy first followed by the Third Eye colonoscopy, and the other half will have the Third Eye procedure first.

Results from the two groups will be analyzed and compared to determine the effectiveness of the Third Eye Retroscope for detecting additional adenomas and other polyps compared with the standard colonoscope alone.


Options:
A: Inclusion Criteria:

1. Age 18 years or older.
2. Informed written consent

Exclusion Criteria:

1. History of inflammatory bowel disease.
2. Patients with severe cardiopulmonary disease precluding colonoscopy.
3. Presence of conditions not allowing for polypectomy or biopsy (e.g. coagulation disorder).
4. Known familial polyposis syndrome (FAP, HNPCC, Juvenile polyposis, etc)
5. Sub-optimal preparation for the procedure, which will be determined by patient history or based on the initial colonoscopy.
6. Pregnancy
B: Inclusion Criteria:

* all persons willing and able to undergo screening colonoscopy over the age of 55 years

Exclusion Criteria:

* any condition not compatible with the definition of screening colonoscopy
C: Inclusion Criteria:

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

Exclusion Criteria:

* Patients with a history of colonic resection;
* Patients with inflammatory bowel disease;
* Patients with a personal history of polyposis syndrome;
* Patients with suspected chronic stricture potentially precluding complete colonoscopy;
* Patients with diverticulitis or toxic megacolon;
* Patients with a history of radiation therapy to abdomen or pelvis;
* 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.
D: Inclusion Criteria:

* Subject between the ages of 18 and 70
* The patient is undergoing colonoscopy for screening, for surveillance in follow-up of previous polypectomy or for diagnostic workup;
* Written informed consent must be available before enrollment in the trial
* For women with childbearing potential, adequate contraception

Exclusion Criteria:

* Patients with a history of colonic resection;
* Patients with known (or newly diagnosed) inflammatory bowel disease;
* Patients with a personal history of polyposis syndrome;
* Patients with suspected chronic stricture potentially precluding complete colonoscopy;
* Patients with diverticulitis or toxic megacolon;
* Patients with a history of radiation therapy to abdomen or pelvis;
* Patients with acute lower GI bleeding
* 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.

Answer: C