Baby's poop

Hello mga momshie, my baby ( 3 mos po sya bukas)has been having 2 to 3 runny poops each day for the last 3 days (she normally goes once a day or once every 3 days).btw, he is breastfeed.. Is this diarrhea? How do you tell diarrhea in a baby? If it is, what should I do? #1stimemom