dairy free for crohns

Hi, my son tarran who is 12, was told he had crohns 1 1/2 years.He is on his second course of steriods has also done 9 weeks modulem feed,has been on 3000mg aday pentassa for 1 1/2 year and is now started azathoiprine.I would love some feed back if a dairy free diet would help or any other info on what food helps .The crohns is now in his tummy,is this any worse than in the large and small intestine,were his has always been.

thanks alot

allie