Do you need to have an analgesic for colonoscopy? is diprivan common?

Not necessarily but: Most people prefer to have sedation for a colonoscopy and Diprivan is often the drug used for its rapid but short acting profile.

Not necessarily.: You don't need to have any sedation or analgesia for a colonoscopy, but it depends on your response to pain and your colon anatomy. I had my colonoscopy wide awake without sedation and went to work right afterwards. Diprivan is relatively common and depends on physician or regional preference.