gube?

ok so i KNOW vince needs a gtube..he is 2 1/2 years old..he was born at 8 pounds 6 oz...he gained fine once on enzymes and always has since (for the most part) at 9 months old he was admitted with pnemonia (his worst one) and at that time ate french fries/ice cream/jelly...once home he quit eating EVERYTHING! baby food went from 2 jars down to 1/2 and he would gag on anything else i offered even his cereal...he eventually started eating cherrios and fruit snacks and vanilla yogurt...he was put on pediasure at 10 months for nutrtional value..as he got older he refused and gagged on more and more...at 18 months and we switched clinics and he was put on a higher calorie formula..but is still refusing the enzymes...he never had to many greasy problems...so now that high cal formula is no longer working..even when increased..and when increased it is blisterin his butt...i KNOW he needs enzymes/vitamins/acid reducer/salt/allergy meds....but that is really not easy in our situation..no matter what we do he usually pukes from forcing those things...our entire famil in now in agreement that vince should definitly get the gtube...the dr's just say they dont want to perform the surgery for "no reason" he has not eaten in almot 2 years and has gotten worse...what makes them think he is gonna eat out of the blue? so my question is how do i cnvince the dr's that its time...he needs this tube? he is very aggressive and i've heard it can mean he is hungry...he also whines alot he will say he wants more milk/yogurt ect but then begins gagging...so advice?