I understand your concern. Vomiting for one day in a young child is usually due to a mild stomach infection which occurs not only through outside food, but by drinking contaminated water or not washing hands properly before eating. When a child comes to me with vomiting, I suggest they have Ondansetron syrup half an hour before food or drink. Some guidelines you could follow are to give him more of fluids like tender coconut, juice if he feels nauseous on seeing food. Do make sure he washes his hands well before eating and after using the toilet, as children his age tend to touch dirty items and not spend enough time washing hands well. Warning signs you should look out for: 1. Persistent vomiting 10 times/day 2. Blood in vomit 3. High fever Temp 102 F 4. Severe headache If any of the above are present, kindly take him to see a pediatrician. Hope this helps. If you have further questions, feel free to ask them. Wishing him a speedy recovery