I am worry about my 5 months old baby has not poo for 4 days. Should I take her to see doctor?

As what Idza mentioned, it is not uncommon for babies to not have any bowel movements for a few days. As long as the infant's stools are soft, he/she is not constipated. Signs to watch out are when: - breastfed babies did not have any bowel movements for more than three days; five days for formula-fed babies - Stools are hard and pebbly, or much thicker than peanut butter - Stools are thin, watery (could be diarrhea) - Stool is red or black (could indicate bleeding) - Stool is white (could indicate that baby is not properly absorbing nutrients) If you observe any of these signs, it is best to bring your baby to the doctor.