AIM: To evaluate the new Retro View~(TM) colonoscope and compare its ability to detect simulated polyps “hidden” behind colonic folds with that of a conventional colonoscope, utilizing anatomic colon models.METHODS: Three anatomic colon models were prepared,with twelve simulated polyps “hidden” behind haustral folds and five placed in easily viewed locations in each model. Five blinded endoscopists examined two colon models in random order with the conventional or Retro View~(TM) colonoscope, utilizing standard withdrawal technique. The third colon model was then examined with the Retro View~(TM) colonoscope withdrawn initially in retroflexion and then in standard withdrawal. Polyp detection rates during standard and retroflexed withdrawal of the conventional and Retro View~(TM) colonoscopes were determined. Polyp detection rates for combined standard and retroflexed withdrawal(combination withdrawal) with the Retro View~(TM) colonoscope were also determined.RESULTS: For hidden polyps, retroflexed withdrawal using the Retro View~(TM) colonoscope detected more polyps than the conventional colonoscope in standard withdrawal(85% vs 12%, P = 0.0001). For hidden polyps, combination withdrawal with the Retro View~(TM) colonoscope detected more polyps than the conventional colonoscope in standard withdrawal(93% vs 12%, P ≤ 0.0001). The Retro View~(TM) colonoscope in “combination withdrawal” was superior to other methods in detecting all(hidden + easily visible) polyps, with successful detection of 80 of 85 polyps(94%) compared to 28(32%) polyps detected by the conventional colonoscope in standard withdrawal(P < 0.0001) and 67(79%) polyps detected by the Retro View~(TM) colonoscope in retroflexed withdrawal alone(P < 0.01). Continuous withdrawal of the colonoscope through the colon model while retroflexed was achieved by all endoscopists. In a post-test survey, four out of five colonoscopists reported that manipulation of the colonoscope was easy or very easy.CONCLUSION: In simulated testing, the Retro View~(TM) colonoscope increased detection of hidden polyps. Combining standard withdrawal with retroflexed withdrawal may become the new paradigm for “complete screening colonoscopy”. AIM: To evaluate the new Retro View ~ (TM) colonoscope and compare its ability to detect simulated polyps “hidden ” behind colonic folds with that of a conventional colonoscope, utilizing anatomic colon models. METHODS: Three anatomic colon models were prepared, with twelve simulated polyps “hidden ” behind haustral folds and five placed in easily viewed locations in each model. Five blinded endoscopists examined two colon models in random order with the conventional or Retro View ~ (TM) colonoscope, utilizing standard withdrawal technique. The third colon model was then examined with the Retro View ~ (TM) colonoscope withdrawn initially in retroflexion and then in standard withdrawal. Polyp detection rates during standard and retroflexed withdrawal of the conventional and Retro View ~ (TM) colonoscopes were determined. rates for combined standard and retroflexed withdrawal (combination withdrawal) with the Retro View ~ (TM) colonoscope were also determined .RESULTS: For hidden pol yps, retroflexed withdrawal using the Retro View ~ (TM) colonoscope detected more polyps than the conventional colonoscope in standard withdrawal (85% vs 12%, P = 0.0001). For hidden polyps, combination withdrawal with the Retro View ~ (TM) colonoscope Detected more polyps than the conventional colonoscope in standard withdrawal (93% vs 12%, P ≦ 0.0001). The Retro View ~ (TM) colonoscope in “combination withdrawal ” was superior to other methods in detecting all (hidden + easily visible ) polyps, with successful detection of 80 of 85 polyps (94%) compared to 28 (32%) polyps detected by the conventional colonoscope in standard withdrawal (P <0.0001) and 67 TM) colonoscope in retroflexed withdrawal alone (P <0.01). Continuous withdrawal of the colonoscope through the colon model while retroflexed was achieved by all endoscopists. In a post-test survey, four out of five colonoscopists reported that manipulation of the colonoscope was easy or very easy.CONCLU SION: In simulated testing, the Retro View ~ (TM) colonoscope increased detection of hidden polyps. Combining standard withdrawal with retroflexed withdrawal may become the new paradigm for “complete screening colonoscopy.”