I haven't had any other surgery, but I usually clear stuff through my GI nurse, especially if they want you to take any additional meds - like pain meds that might contain NSAIDS which are a no-no for us. You don't want to start a flare from having another surgery if possible.
I would also make sure the surgeon/staff are aware of your condition and any Crohn's meds you might be on. Good luck Mary!