The sedation used in the US most often is Versed. It is an amnesiac and does nothing for pain. "Its called conscious sedation." The rest of the "cocktail", the actual "pain killer" is usually demerol or fentanyl or alfentanyl. The theory is if you do feel pain, you won't remember it. You are aware enough to respond to instructions from the doctor and tech but you won't remember it. This also allows them to administer less pain medication.
IF your "scopist" is considerate of his/her patients, rather than the tiime involved, and assuming you don't have some serious colon involvement or rectal problems it is not a painful procedure. It can be uncomfortable.
The interior colon has no "nerves" to feel when a biopsy is taken, etc. BUT when it is stretched due to too much air insuflation or more likely due to the scope shaft looping back on itself then one can feel pain. Thus w/o conscious sedation or anesthesia the "scopist' needs to proceed much more slowly thru the entire procedure.
A Study of Pain During Colonoscopyhttp://www.e-health-questions.info/html/board/index.php/action=displaythread&forum=boweldisorders&id=12&realm=default
Why Colonoscopy Is More Difficult In Women
I like to watch the monitor thru out the procedure. I wanna see for myself what's going on in there which is why I prefer NO SEDATION but I do have some demerol and sometimes when we run into difficulty manuvering thru the transverse colon near the hepatic flexure the vagus nerve gets ticked off and my gastro has to add a little phenergan to stop the dry heaving the vagus nerve can cause. Not every time but on two scopes I've had we had to use the phenergan.
I've been told that those women who have had a hysterectomy can have a little more difficulty w/the scope manuvering across the transverse colon because there is more room for the transverse colon to dip lower.