A.F.
I agree with the other posters, he may not want to eat right now because he's still getting over the bug, or remember throwing up and how it made him feel, so is affraid to eat much at the moment. If you are concerned about his nutrition, then I suggest Pediasure. It's like old people Ensure, but for kids. My 9 year old was VERY picky when she was your little one's age, and wouldn't eat anything, I was so concerned that I talked to my Dr about it, and he said the same thing the other poster said..."She's not going to starve, she'll eat when she gets hungry" although he suggested I give her some Pediasure to make sure she gets the nutrition she needs. So I gave her at least 1 or 2 a day in a sippy cup, because she didn't have any problem in drinking anything, just eating, and after a couple of months, she suddenly started eating the things the rest of us were eating. I don't make seperate meals for any of my kids, they eat what I provide, or they don't eat. Of course I make things that they all like, I don't intentionally make Brussel Sprouts or anything, knowing they won't eat it.
A.