If he has completed one year of age,stop breastfeeding and bottle feeding if given,give just 2 milk feeds using a glass or spoon and katori and 4 solid meals a day including curd and Banana in the diet in addition to whatever you prepare at home. Give ors after every loose motion if watery and add Enterogermina vial one vial twice a day for 5 days. If not improving OR accompanied by other symptoms like vomiting or fever or dullness and refusal to feed consult with your paediatrician.