Could it be crohn's?

My son is 10 years old and has been suffering from pain/nausea above his belly button since 3.  He cannot eat anything which contains fat as he gets a tummy ache.  He gets nausea when playing soccer,  Pain always above belly button.  Hes been on losec/iron pills for 2 years.  Recent bloods show low serum iron levels, normal ferritin levels, normal red blood count and high in inflammation.  What could be causing this?  He has never had diahorrea though.  But could these symptons be crohn's?