The goal of this research is to conduct a pilot clinical study to image colonic polyps with the intent to evaluate the potential use of Optical Frequency Domain Imaging (OFDI) to identify the extent of invasion (if present), differentiate between hyperplastic polyps and adenomas, and identify serrated polyps.

The colon OFDI catheter will be used in conjunction with a sigmoidoscope. If a sigmoid polyp is identified, the colonoscope will be removed and a sigmoidoscope inserted. The colon OFDI catheter will be advanced through the sigmoidoscope accessory port and positioned adjacent to the colon wall. Imaging will be performed with the OFDI system across the polyp's surface and the base/stalk if pedunculated. The investigators anticipate that on average the investigators will utilize 4 helical scans per polyp. Each of the scans will take less than 30 seconds.

Inclusion Criteria:

• Patients undergoing a screening colonoscopy
• Patients must be over the age of 18
• Patient must be able to give informed consent

Exclusion Criteria:

• Patients with hemostasis disorders
• Patients taking any anti-coagulants such as Coumadin or Plavix,