Silkrose - if you rely on Codeine DO NOT COME TO THE UAE - it's illegal, and people have been jailed for a number of years (4 I think) for possessing it. (Genius huh?)
If you can use another med for pain relief you might be OK, btu check with an aviation Dr if Crohns disease will have an impact on getting an aviation medical. I don't think there is any restriction, but you might as well get someone better qualified to answer that.
If you do decide to go to the open day, definitely wear business dress.
Good luck.