Hello and Welcome to Ask A Doctor service. I have reviewed your query and here is my advice. You describe your infant has having acute gastroenteritis(vomiting and diarrhea). This is most likely due to a virus. Does he attend daycare where he could have acquired the virus from the other children? The initial concern is he dehydrated? Signs of dehydration include: - Does not make tears when he cries - Dry lips, tongue, and mouth - When you gently pinch the skin over his abdomen, it feels doughy and takes 2-3 seconds to fall back into place -He wets his diaper with less frequency than when he is well Does he have a temperature greater than or equal to 101 degrees? If he does not show signs of dehydration and does not have a high temperature, it is safe for you to keep him at home. I recommend that you give him nothing by mouth for the next 4-6 hours. If he does not vomit during this period, then offer him a couple ounces of room temperature Pedialyte or apple or pear juice. Cold fluids will cause his stomach to cramp. After another 2-4 hours, again if there is no vomiting, you can offer your son 3-4 ounces more of fluids. You may continue this protocol for another 1-2 times. If at any time. After he retains fluids for the first time, he indicates he wants something to eat, then you may give him a small amount of anything he would like. Acute viral gastroenteritis usually runs its course in a week or so. Hope I have answered your query. Let me know if I can assist you further. Arnold Zedd, MD, FAAP