Hi Bing Qi,
A colonoscopy often begins with the administration of a mild sedative which renders the patient unconscious or drowsy for the duration of the procedure.
After which, the colonoscope is inserted into the anus, gas is pumped into the colon and the scope is advanced to the caecum. This is done by a series of maneuvers executed by the endoscopist’s right hand which twists, pulls and pushes the scope, while the left hand manipulates the up-down-left-right controls on the scope handle.
This allows the scope to wriggle its way through the bends and corners of the colon.
