Background: Variable stiffness (VS) colonoscopes allow passage of the rectosigmoid in a flexible mode followed by stiffening to prevent looping. In this study cecal intubation time was compared with 4 Olympus colonoscopes: standard adult CF-140(SA), standard pediatric PCF-140 (SP), VS adult (VSA) and VS pediatric (VSP). Method: All exams were performed by a single experienced examiner. 110 were excluded for the following reasons: colon resection (N=42), pediatric scope selected for stricture, known severe diverticulosis, etc. (n=24), IBD (n=32), failed colonoscopy at another facility (n=6) acute GI bleed (n=6). For 355 remaining consecutive sedated examinations, scopes were rotated with scopes left out of rotation if they were not yet sterile or needed repair. All patients were sedated independently by nurses. Results: 99.2% of exams were complete to the cecum. The stiffness device was activated in 61% of VSA and 80% of VSP exams. The number of exams with each scope was SA n=125, SP n=92, VSP n=75, VSA n=63. There was no difference between scope groups in percent male (55%), mean age (55 years), or percent of women with prior hysterectomy (44%). The examiner judged the device very useful, somewhat useful and no help in 46%, 44% and 10% of VSA exams and 55%, 33% and 12% of VSP exams Mean cecal intubation time in minutes for SA was 4.09, SP 4.05, VSP 4.04, VSA 3.93 (P=0.98). The percent of intubations in 5 min 23.7% with no difference between scopes. Nurses assessment of pain was not different between scopes (p=0.8). Use of abdominal pressure was numerically lower with VS scopes (44% vs. 53%), but not significant (p=0.4). Conclusion: VS scopes were frequently judged useful by an experienced examiner but did not impact cecal intubation times. Additional studies by other experienced and inexperienced examiners as well as evaluation of additional technical improvements and evaluation in unsedated patients are needed.