Childbirth without drugs is possible and not absurd (speaking as a dad who withnessed, not experienced it, twice.) Colonoscopy without conscious sedation is another story, something you don't wanna do. (Listen to Weak Link and the others.)
My experience as a nurse who has seen lots and lots of patients come back from colonoscopies is that nobody ever says anything bad about the procedure. They don't remember nothin' unpleasant. Could it be because of the drugs? Yep!