Hi What is the frequency of stools? Do you see blood in the stools? Does he run high fever? If you see blood in stools its mostly due to bacterial infection and will need antibiotics. But below 2 yrs, most common cause is virus that presents with vomiting, watery stools with increased frequency and fever. In such a case antibiotics are not needed. If he is on breastfeeds, continue that. Avoid cow`s milk, fruit juices. Give him rice based foods, vegetable soups, lots of curd. You may also give him porridges made from rice, roasted bengal gram and sago. There are no medicines to stop diarrhea immediately. You can give him probiotics like Econorm that comes in sachets which will reduce the duration of the illness. Be sure he drinks lot of fluids and passes adequate urine atleast 4 to 5 times a day. If at any time you find your son very tired, food intake is very less or having high fever, do take him to a pediatrician immediately. Hope you find my answer helpful.