i had one like about a year ago, the worst partwas having to not eat anything solid for like 2 - 3 days prior and then the day of having to drink a freaking GALLON of medicine in an hour( to clear my system), that was the sickest thing ive ever had. i dont know if you have to do all that. My colonoscopy was to get a biopsy of the villi's on my intestine. As for the procedure itself, i dont really remember much of it, they completely knocked me out. I do remember afterwards I was kept in a room with other patients who had air pumped into theyre digestive systems i think and they were farting like crazy. Hopefully i wont have to have one again. Endoscopy's are much better.