I'm from Greece, and I know many people here who are on Remicade, they get their infusions in the local hospitals with no problem. If I was in your shoes, I would search or contact some big hospitals in Prague, just to be on the safe side, and of course I think you should get a letter from your GI explaining your situation and the current medication you are on. Remember, Crohns is not so common in these countries including Greece of course, that's why it's very important to be fully prepared when you go there. And yes, Prague is a wonderful city, you will love it!!!
Christina