When you give food forcefully or if they don't like it some children may vomit. Is it vomit or just spitting out?? Vomiting can be due to stomach causes. Spitting can be due to forcing or throat irritation or dislike of food. Look for any other symptoms associated. Are there any ulcers in the mouth?. Show to your pediatrician if any other symptoms are there or if vomiting is more. Hope this helps.