I agree with Jojo. The prep will make you do the same thing anyway and clean you totally out. Not a doctor but unless you're really ill with a virus or something and this a one off from eating crap, I wouldn't sweat it.

The prep is the worst part. Just make sure you have a good book or your phone/laptop is charged because I think you can guess where you'll be spending some time

The procedure itself is a breeze. You're going to get some good drugs (and if they don't offer, ask!) and you won't give hoot or remember

Positive thoughts