If a baby has not had a bowel movement for five days, a physician needs to be consulted. WebMD advises that if a newborn has not had a bowel movement since the delivery day, a mother can try a new brand of formula or add prune juice to milk.
WebMD points out that breast milk is so high in nutrients that most of it is absorbed by a baby's body, leaving very little left for a bowel movement. Newborns often go as long as a week without having a bowel movement, which is completely normal. Mothers need only be concerned if the stools are unusually hard, bloody or dark colored. If the baby looks uncomfortable or in pain during a bowel movement, or if the baby's abdomen is swollen, then there needs to be some intervention.
Baby Center states that as long as a baby is feeding, the occasional lack of any bowel movements in a day is usually not an issue. A newborn's stools are usually dark green. This is due to a substance that accumulates in the baby's intestines while in utero. The stools lighten to a yellow color after breastfeeding. However, stools do vary in color and consistency depending on what the mother is eating or the type of formula the baby is fed.