Newly-month-old babies do not poop may be insufficient diet, imperfect digestive system and congenital intestinal diseases and other reasons. 1. Insufficient diet: when the new-month-old baby intake of breast milk is insufficient, the amount of milk powder is reduced or the concentration is too thin, the intake can not meet the baby’s needs for growth and development, thus appearing in the phenomenon of reduced stool or even not pooping. After giving enough milk, the stools can return to normal. 2. Digestive system is not perfect: the baby’s body is in the stage of development, so its digestive system is not very perfect. After the baby has eaten, incomplete digestion may lead to a decrease in full-term baby’s bowel movements, or even the situation of not pooping. 3. Congenital intestinal diseases: If the baby suffers from congenital hidden intestinal diseases such as congenital anal stenosis, it will lead to the stool is not easy to discharge. The disease has no obvious symptoms in the early stage, and can be accompanied by bloating, vomiting and other symptoms in the later stage. Parents are advised to take their newborn babies to the hospital to identify the cause of the disease and get prompt treatment when the baby does not poop.