The baby’s lack of poop is considered to be caused by factors such as enhanced digestive function, constipation and macrocephaly. 1. Enhanced digestive function: As the baby’s digestive system continues to improve, its digestive function will gradually enhance, so that it can better digest and absorb breast milk, therefore, the food residue produced every day will be reduced, and is not enough to stimulate rectal defecation response, which leads to the baby does not poop, but the spirit of the head is good, no pain performance. 2. Constipation: If the baby’s intake of dietary fiber is too low due to partiality or picky eating, or if the baby is afraid of defecation due to painful defecation, constipation can be triggered, resulting in the child having less than 3 bowel movements per week, dry stools that are not easy to pass, or when defecation is occurring, it is accompanied by crying and other phenomena. 3. Congenital megacolon: the etiology is unclear, mostly due to the interaction of genetic and environmental factors, the newborn will be delayed discharge of fetal stools, and infants show stubborn constipation, abdominal distension and other symptoms, and can be difficult to feed, developmental difficulties and other phenomena. There are many other reasons why babies don’t poop, it is recommended to take your baby to the hospital in time and follow the doctor’s instructions for treatment.