Re: fussy hungry baby
Changes in poop frequency are very normal throughout the first year. After 6 weeks, breastfed babies may go as often as several times per day or as little as once a week. As long as weight gain is normal, baby is being nursed on demand and not on a schedule, wet diaper output continues to be normal, and baby doesn't seem to have diarrhea (stools will be excessively watery and foul-smelling), a change in poop frequency is nothing to lose sleep over.
It's very normal for a baby to eat a large amount from the bottle even after a perfectly satisfactory nursing session. Babies love to suck, and when they suck on a bottle they must swallow or they will choke because the bottle delivers a rapid flow regardless of how hungry the baby is. This is totally different from the way a baby sucks on the breast: the breast delivers a lot of milk only when baby is doing the rhythmic, purposeful nutritive suckling, and not the light, fluttery comfort suckling. When a baby comfort-sucks, the milk flow is very slow or sometimes stops altogether.
If a baby is hungry and nurses properly, she will get fed regardless of how empty the breast feels. It may take more time and effort than she likes, but she will get fed. And the intense suckling will stimulate the breast to make more milk. Now, if you short-circuit this feedback system by offering bottles whenever the baby seems excessively hungry/fussy, there's a chance that baby won't learn how to work for a meal and will just start demanding bottles whenever the milk isn't super easy to get at.
I really think the thing to focus on here is not the empty feeling, not the baby's willingness to take a bottle, not the fussiness, but the fact that your baby is having more than adequate diaper output. If it comes out, it had to go in!
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!"