Why do babies defecate on themselves?

Babies defecate on themselves primarily due to their immature digestive systems and lack of control over their bowel movements. At birth, they have not yet developed the muscle control necessary to hold in stool, and their diet consists mostly of liquid (breast milk or formula), leading to frequent bowel movements. Additionally, infants are not yet aware of the social cues or signals associated with using the toilet. As they grow and develop, they gradually learn to control their bowel movements.