Three-month-old babies five days no stool belongs to abnormal. The normal frequency of defecation for a three-month-old baby is once every one to two days. It is not normal for a three-month-old baby to have no bowel movement for five days, and the child may have gastrointestinal dysfunction, which is mainly due to the fact that the infant’s gastrointestinal function is not yet fully developed. In this case, excessive milk intake or changes in the quality of milk may lead to gastrointestinal disorders. These infants need dietary adjustments, mainly by reducing the amount of milk consumed at each feeding, increasing the frequency of milk consumption, drinking a small amount of water between feedings, and the children can take bifidobacteria to improve the environment of the intestinal flora. Infants with abdominal distension, crying, fever and other symptoms, timely hospital consultation, under the guidance of specialists.