The RetroView 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 RetroView colonoscope in retroflexed withdrawal alone ( P < 0.01 ) .