Hi, my son is three now. When he turned one, he suddenly refused to eat/drink almost everything for 3 months ! Trips to the PD proved useless too, he said that as long as my son was not loosing weight, there's nothing to worry about. But i was worried sick, so i can understand how you are feeling now, but as long as your son is healthy i thnk you shouldn't worry too much. Have you tried yoghurt? During that three months, my son practically survived on that alone. Good Luck!