They do not get hair balls…., as long as he is drinking water, not dehydrated and eating the chick and rice (use white rice as easier to digest then brown rice), I would see if he keeps that down. If he is, I would keep him on that for 3 or so days, then add back in his normal food over 2 days or so. And a pepcid once a day also...
What are you feeding him normally? Many times you can get a bag of food that is bad or have a bag go bad. If he is keep the chicken and Rice down, I would suggest you get a new bag of food