she may be irritable and cranky but it is not because she isn't pooping eight times a day. she probably has colic (fussy lots of gas etc. ). get used to it because it tends to last until she is about three months old. we call it the rule of threes: a child over three weeks and under three months who cries more than three hours a day more than three days a week. babies don't have a lot of flora (bacteria) in their colons to have a big poop so they can go a long as 8 days without a bm if they are being breast-fed so every other day is really good. read about "colic" and ask her pediatrician for some advice.
my 3 week old only poops every other day and strains to go everyday and nothing what can i do. she doesn't poop everyday she poops every other day and strains all day to poop again but does not poop and grunts what can i do cause she irratible and cranky