help for my 4 yr old FTT son

Hello, I am hoping you can give me an opinion or  advise?  My sone was diagnoised with failure to thrive when he was 2 and also central core disease. He is 4 1/2 yrs old 37 in and 26.5 lb. We have seen many specialist and many tests that come back all normal and the only advise is to get him to eat more food, does not work. He continues to gain a little to just turn around an loose it. He has not had any weight gain in 1 yr. What could I expect from endo and is this a speciality that we should be looking at. Thanks a very concerned mother   Laura

[margypops]

Could you tell us why eating more does not work'  what food do you give him, could you give us an idea of this diet in a 24 hour period ,does he drink a lot of milk?