The purpose of this study is to identify if performing diagnostic colonoscopy with a small plastic cap attached to the camera will improve performance of colonoscopies by physician trainees.

Training novice endoscopists to perform effective diagnostic colonoscopy is a central objective of Gastroenterology fellowship. Though there is no universal definition of competency, it is traditionally assessed with a combination of objective measures such as volume of procedures and subjective factors such as formal evaluations. As quality measures such as cecal intubation time, cecal intubation rate, and adenoma detection rate gain in importance in clinical practice, they should be increasingly incorporated as objectives into more formalized and objective training methodologies.

Indeed, though 140 colonoscopies have been suggested as a rough volume threshold needed for trainees to gain competence, evidence suggests that the number may actually be much higher when taking various objective quality measures into account.

Recent attention has turned to various measures to improve trainee performance such as computer simulation and magnetic endoscopy imaging. Along these lines, simple, effective, and economical measures are needed to improve trainee performance.

Cap assisted colonoscopy (CAC) is performed with the aid of a transparent inert cap attached to the distal end of the colonoscope. CAC allows close examination of mucosa proximal to flexures and haustral folds and prevents "red out" when closely approximated against mucosa, aiding in luminal orientation and examination. CAC has been shown to improve cecal intubation time, polyp detection rate, and adenoma detection rate in the hands of experienced practitioners. A handful of studies have also indicated that these benefits also extend to trainees, while another prospective study showed no improvement in cecal intubation rate.

The investigators hypothesize that cap assisted colonoscopy will result in significantly improved cecal intubation rate and time, as well as adenoma detection rate, among trainees when compared with standard non cap assisted colonoscopy in a large academic Gastroenterology training program in the United States.

The study is a prospective randomized trial of colonoscopies performed at Harris Health System Ben Taub Hospital by all novice endoscopy trainees from July 2015 until enrollment is complete. Novice endoscopy trainees are defined as endoscopists with less than 10 colonoscopies performed by July 2015. All colonoscopies included will be performed by the novice endoscopist under direct supervision of a board certified attending gastroenterologist.

Each colonoscopy fulfilling the inclusion criteria will be randomized with equal probability to a cap assisted colonoscopy (CAC) group or a control standard colonoscopy (SC) group.

Inclusion Criteria:

• All patients undergoing colonoscopy by a novice endoscopist

Exclusion Criteria:

• Age less than 18 years or greater than 90 years.
• Pregnancy.
• Prior surgical resection of colon or rectum.
• Known obstructing colorectal tumors.
• Severe hematochezia.
• Diverticulitis within 1 month of procedure.
• Clinical or radiological evidence of colonic obstruction or megacolon within 1 month of procedure.
• Referral for endoscopic mucosal resection.
• Unsedated colonoscopies.
• Colonoscopies abandoned due to inadequate bowel prep or colonoscopies with Boston bowel prep score < 3.