Setting: Outpatient colonoscopy in a single VA hospital Methods: After informed consent and standard bowel preparation, patients received pre-medications administered as 0.5 increment of Fentanyl (25 μg) and 0.5 increment of Versed (1 mg) plus 50 mg Diphenhydramine. The conventional and the study method for colonoscopy were implemented as previously described. Additional pain medications were administered at the patients' request.