Dear Robin,
The same thing happened to my son when he was about three he was fine for nine months and than we started having problems again. Even though it seemed as if he was fine they told me he was silently refluxing the whole time and because he had been sick since birth he showed it in other ways. Unfrotunately he has been sick since that small break. I hope you get some anserws and your son gets some help.
Rhonda