M.A.
Are you seeing a regular pediatrician or a Pediatric Gastrenterologist? Tested for celiac and other food allergies? Try probiotics to set up goog bacteria. He may be allergic to things other than dairy. Most people think Lactose free is dairy free - my son is allergic to Casein (the protien in milk) it is in almost all processed foods even hot dogs frozen chicken and soy cheeses. Just because something says dairy free does not mean casein free. I don't know where you live but there is an excellent Dr, in Baton Rouge that deals with these and other things. Her name is Dr. Stephanie Cave.