Hello and welcome to HCM. Thank you for your query. Whenever it comes to children, we cannot base a diagnosis just on symptoms, as children present differently and unlike adults, do not express well enough what they are experiencing. Keeping this in mind I request you to take your child to a child specialist first. But, from the description provided this could be two of the following things: -A stomach upset (due to introduction of foreign or contaminated food) leading to indigestion -Stomach flu (eg. gastroenteritis, etc.)--but child will usually be sick and lose appetite As you have not mentioned any other symptoms, they cannot be included in the above list, but there still is a possibility of other causes being present. This can be found only by a doctor. In the meantime, please keep your child hydrated, as much as possible, as the loss of fluids in the form of diarrhea can lead to other complications. Avoid fried/oily/fatty food and supplemental milk, dairy products and gluten products until your doctor tags them to be safe. I hope I have succeeded in providing the information you were looking for. Please feel free to write back to me for any further clarifications. I would gladly help you. Best wishes.