A one-month-old baby who doesn’t poop for three days may be caused by physiological factors (such as enhanced digestive function, etc.), and no special treatment is needed. However, it may also be caused by pathological factors (such as constipation, megacolon, etc.), and massage and medication can be taken to improve the symptoms. 1. Physiological factors: (1) Enhanced digestive function: after the birth of the baby, the digestive system continues to improve, the digestive enzymes in the intestinal tract also gradually increase, so that the baby’s digestive function is enhanced, resulting in the baby can be fully digested and absorbed breast milk or formula, producing less food residue, not enough to produce defecation reflexes, resulting in the baby did not poop for three days, usually not accompanied by other discomforts, the case does not require treatment, observation can be. 2. Pathological factors: (1) constipation: the baby can not poop for three days, and the stool is dry and not easy to discharge, the baby can cry because of the pain of defecation. Parents can clockwise massage pediatric abdomen, help intestinal peristalsis, promote defecation. If necessary, oral bifidobacterium bifidum can be prescribed to regulate intestinal flora, lactulose to soften stools, etc., to improve the symptoms. (2) Macrocephaly: the baby may not poop for three days, and may be accompanied by feeding difficulties. Prompt medical attention is needed to relieve the symptoms with the use of cecrops or colonic enemas as prescribed by the doctor, and to assess whether surgical measures are needed. In addition, there are many other reasons why a one-month-old baby does not poop for three days, such as intestinal obstruction, etc. It is recommended to consult a doctor in time to rule out physiological factors and receive treatment as soon as possible. The above medications should be used according to medical advice.