- prior surgical resection of any portion of colon, prior history of colon cancer, history of inflammatory bowel disease, use of anti-platelet agents or anticoagulants that precludes removal of polyps during the procedure, poor general condition or any other reason to avoid prolonged procedure time, history of polyposis syndrome or HNPCC, inability to give informed consent, inadequate bowel preparation, allergy to fluorescein, pregnancy, and renal insufficiency.