My baby is having one bowel movement every three to four days. She's 4 months old and is breastfed. Is this normal?
Yes, it is. Your daughter is eating perfect food, one that has been custom-made just for her. As her intestines mature and she is able to digest your breast milk more completely, the amount of waste your baby produces is naturally decreasing--which means she now can go for days without having to poop. This pattern often begins at about 6 weeks of age and can continue for the entire time a baby is exclusively breastfed, which is until the age of about 6 months in many families.
That said, if your daughter seems to be very uncomfortable when passing bowel movements or if she is having hard stools (neither of which are normal for a breastfed baby), be sure to talk with your pediatrician. But if she is growing well, smiling, peeing and pooping without pain, everything should be just fine.