My Son Is 4 Years Old And He Has Been

My son is 4 years old and he has been sick from last 4 days. He vomited almost 10-12 times very first day of him being sick. Second day he was completely fine but from last two days je has started throwing up again. But this time it's less than the first day. He is having stomach ache right in the middle of his stomach followed by vomit. He is throwing up right after being fed even water. I am trying hard to maintain his hydration. Even went to prompt med, as it seems gastroenteritis, they gave us a medicine to stop the vomit. But I am not sure the infection has settled yet. Please help. My fear he is not having appendicitis.