Hi welcome to health care magic... Your child having acute gastroenteritis from outside food....so he has having food poisoning. .. Ciprofloxacin antibiotic for five days given empirically.... For spasm relief dicyclomin can be given... Take small meal with frequent interval... Avoid excess spicy foods, excess tea and coffee, excess fried veg etc... Cooked oatmeal will help in soothing stomach... Drink more water... If not improving than stool culture, USG abdomen done for further work up and specific treatment accordingly.. Hope your concern solved Take care