Oh boy... hopefully you're playing Ultimate somewhere there's a bathroom nearby...
Anyway, if you eat/ate anything like I used to, I'm sure you've got something in there. Even people who eat healthy nearly all the time managed to get stones. colonics you could probably get from some sort of colonic practicioner in your area. I've personally never had one done. I don't see it being really necessary to do either, but I guess it can't be harmful, right? Actually, it might be harmful to your self-esteem if you tell your friends about it.. ;o)
Er, anyway, drink a lot of *apple* juice and eat mostly fruits and veggies until then.
Good luck - for me, the verdict's still out on whether this will improve my complexion or not.