maraming pwedeng dahilan mamsh. mahirap hulaan with little info. pwedeng s simple as di naburp agad, upset stomach, etc. extreme case can be tummy flu or nauntog ng malakas. you need to know ano mga ganap bago sya nagsuka. best to consult your pedia for anything unusual at nakakabahala kasi they can do addl tests.
Minsan po overfeed kaya nagsusuka si baby