Sick Kitten!!!!

I have a kitten who is around 5 months old and became sick today. He threw up yellow bile a bunch of times earlier today and hasn't eaten anything I try to feed him. Usually he will eat anything!! He even runs off with food from the counter. I'm thinking maybe he ate something that went against him??
Just wondering if anyone knows what this is or what I could do for him??

He needs to be seen by the vet to rule out any medical problems.  You can try offering him plain boiled chicken or plain meat baby food, turkey or chicken.