Warning graphical video on Brextin throwing up - if anyone knows of a specialist that can help - please provide advice!

This is a very graphical video showing our son throwing up - this is an everyday event (we do have some days that it doesn't happen, but few) - we have had many swallow studies done and GI tests - but everything comes back as "normal" the doctors just blame it on the brain - (You can now imagine how many stares we get - when this occurs out in public) Often we have no warning. If anyone can provide advice or a doctor that would be willing to help us figure out - how this can be stopped we would be very interested in listening. We have cut out milk and soy from his diet.