I've had several Remicade infusions, for Crohn's. I eventually had to stop treatment with it, but I know lots of people who've done well. As for the younger patients, like your son, I don't know if there's anything in particular to watch for. Your doctor should be the best one to ask, but sometimes they don't know as much as they should.
There have been some recent warnings about Remicade & risk of cancer. Personally, I think it's a question of risk vs. quality of life. Your son is old enough to have a voice in his treatment, but you have the final word. Read and educate yourself...that's about the best I can suggest.
The other thing would be to click on search at the top of this page and search on the word Remicade. There's a lot of info on this message board.
Best of luck to your son and whatever you decide. I'm sure there will be others who will voice their opinions. However, you might get more response on the General Message Board.
My opinion is strictly that, mine. However, if I want your opinion, I'll give it to you. ;-)