Please, contact us immediately and ask for advice. Also, be aware that running to an emergency room and testing your kitten for all possible reasons of the lethargy, vomiting, or diarrhea would be your decision and we are not responsible for any medical bills that you may present to us later. Please contact us first and tell us in a few words what is going on with your kitten. The emergency room should be the last option that you want to consider.