Stop bottle feeding,give 3 each of milk feeds and solid meals a day including curd and Banana in the diet. Give ors after every loose motion if watery. Add Enterogermina vial half vial twice a day for 5 days. If not improving in 3 days OR accompanied by other symptoms like vomiting or abdominal distension or dullness and refusal to feed,consult your paediatrician asap.