Re: 1 month old baby does not poop at al
If her wet diaper output and weight gain is okay, I would just let her be as long as she isn't going more than a week without pooping. By 6 weeks some babies have decreased their poop frequency to just once every week or even less, and some babies reach this point a little earlier than others. 4 weeks isn't out of the range for this change in poop habits to occur. Breastmilk is very easy to digest, and is used very completely, leaving little waste to be excreted.
Coolest thing my big girl said recently: "How can you tell the world is moving when you are standing on it?"
Coolest thing my little girl sang recently: "I love dat one-two pupples!"