Lack of hygiene is the commonest cause of vomiting and loose motions. Give only breastfeeds,and if you HAVE to give top feeds,use ONLY formula milk,not open milk,specially,cow's milk. Use katori and spoon to give top milk,NOT a bottle. Try syp walamycin 5 ml thrice a day,and Enterogermina vial half vial twice a day,both for 5 days. If not improving in 3 days time,switch to injectibles.