What medicines are given before a colonoscopy?

I have to have a colonoscopy done Thursday. They said I will have conscious sedation. The paperwork says I will be given a sedative and pain meds through an IV before they start. Anyone know what sedatives & pain medicines they give you? I wonder b/c I have had 16 surgeries and a lot of pain medicines and sedatives have no affect on me. Any info would be helpful. Thanks!