Looping can prolong colonoscopy, cause discomfort, and preclude a complete examination. A colonoscope with variable insertion tube rigidity may facilitate colonoscopy. Aim: To determine if VRC can facilitate colonoscopy by reducing insertion time (IT) and improving patient acceptability (PA). Methods: Fifty patients were randomized to undergo conventional (CC; Olympus CF-140) or variable insertion tube rigidity colonoscopy (VRC; distal/insertion tube O.D. 13.2/12.9 mm, working length 133 cm, instrument channel I.D. 3.7 mm, view angle 140°, range of motion 180° up/down, 160° right/left; Olympus America, Inc, NY) by the primary investigator. A rotary dial on the handle adjusted the insertion tube rigidity. After reaching the splenic flexure without increased rigidity, maximum rigidity was maintained to the cecum. PA was assessed on a visual-analogue scale(0=most acceptable/no discomfort). Medication dosage(mg midazolam and/or meperidine) was documented, as was the frequency of abdominal pressure (AP), or repositioning (RP). Statistical analysis was performed by the twosample Wilcoxon rank sum test and an extension of Fisher s Exact test (K exact). Results: The groups were comparable in age (median 63 and 65 years VRC and CC, respectively), gender (14 male VRC, 12 male CC), and sedation required (median midazolam/meperidine dose: 4/75 mg, both groups). The cecum was reached in all 25 VRC cases; one patient had failed CC previously. The cecum was not reached in 4 patients in the CC group (2 poor prep, 2 looping). The median IT was 9 min (10.6±1.6) in the VRC group and 10 min (10.6±1.7) in the CC group (p=0.97). PA was better in the VRC group (0.4±0.2 vs. 1.3±0.6, p=0.14 and less AP (0.3±0.1 vs. 1.1±0.4, p=0.05) or RP (0.4±0.1 vs. 1.2±0.4, p=0.46) was required. VRC patients reported less abdominal distention (0.9+.3 vs. 2.2+.5, p=0.05) and had less pain observed by the endoscopist (2.0+.4 vs. 3.2+.4, p=0.06) and the nurse (1.9+.4 vs. 3.3+.4, p=0.05). No complications occurred. Conclusion: VRC facilitated colonoscopy by reducing abdominal pressure and patient repositioning. Although insertion time was not significantly reduced, patient acceptability was better.