Colonoscopy may be an unpleasant procedure. Sedation and/or analgesics is therefore routinely
administered in most countries. In Norway, however, routine sedation is rare, and medication
is normally given on demand, that is, if necessary during the procedure. The investigators
want to evaluate whether the effect of fentanyl, a synthetic opioid with fast onset of
action, is better given before the procedure than during the procedure.