A device in the form of a cuff with concentric finger-like components intended to fit to a flexible colonoscope distal end to stabilize its tip within the colonic lumen and straighten the colonic folds to facilitate observation and/or surgical instrument use. The fingers are intended to open and grip the colon during pull back (exturbation); the device may in addition have a protruding distal end (spacer) intended to maintain distance between the endoscope tip and structures of interest. This is a single-use device.