A 45-day-old baby who doesn’t poop for 3 days may be caused by improper feeding or intestinal dysfunction, etc. The cause can be clarified and then treated symptomatically. 1. Improper feeding: the infant’s diet is not regular, it is easy to cause indigestion and functional constipation, which leads to the situation of the 45-day-old baby did not poop for 3 days. You need to pay attention to the appropriate between the two meals of milk to the baby appropriate water, to develop the habit of eating less and more meals, at the same time you can give the baby clockwise massage abdomen, can effectively promote intestinal peristalsis, to promote the discharge of stool. 2. Intestinal dysfunction: 45 days of infants due to gastrointestinal development is not very perfect, it is easy to be affected by the digestive system, such as formula feeding, due to the milk powder brewed too dry or consume too much, which can lead to gastrointestinal tract digestion and absorption problems, the above situation, the need to develop the habit of eating fewer meals, appropriate massage to promote peristalsis, which is conducive to help the discharge of the stool. If at the same time accompanied by crying, restlessness, bad spirit, abnormal irritability, if necessary, under the guidance of a doctor to use Kesler to help discharge stools. It is recommended that 45-day-old babies who do not poop for 3 days should seek medical attention and active treatment. The above medications should be used in accordance with medical advice.