I would suggest that forcing any child to eat is not the way to help the situation, I am assuming he is on solid food , finger food, if you are spoon feeding him,go onto finger foods, small pieces of chicken, fruits cut up, peas, beans , fish , put them in a dish infront of him then allow him to feed himself, he will enjoy it.You are making a battle otherwise, he vomits because he doesnt want you to spoon feed him, there are mats you can place under their chairto catch the mess. He has no problem other than you are worrying about him eating, take a step back, all will be well , let him be in control. Good luck let us know how he is doing.