The umbilical cord is the “link” between the fetus and the mother, containing the umbilical vein, umbilical artery, yolk tube, umbilical urethra, surrounded by gelatinous tissue, is the mother’s supply of fetal nutrients and fetal excretion of waste products is an important channel. The child needs to be separated from the umbilical cord at birth and detached from the mother’s body; the umbilical cord will fall off about a week or so after birth, forming a localized dry umbilical concavity. If there is persistent discharge or dirt from the navel after birth, it is time to be alert for umbilical disease. Belly button disorders that require surgical intervention in children are mainly related to the degenerative insufficiency of the vitelline duct and the umbilical ureter. The reference to the vitelline duct goes back to the embryonic development of the intestine. The bulk of the human intestine develops from the midgut, which is initially connected to the yolk sac. The rapid growth of the midgut and the small volume of the abdominal cavity, as well as the enlargement of the liver and the development of the middle kidney, led to the loops of the midgut to enter the extra-embryonic body cavity within the umbilical cord, resulting in the formation of a physiologic umbilical hernia in the embryonic stage. At 6 weeks of gestation, the yolk tip was detached from the intestinal loop. At 10 weeks of gestation, the bowel loops returned to the abdominal cavity because of the enlargement of the abdominal cavity, the elevation of the liver position, the degeneration of the middle kidney, and the increase of the negative pressure in the abdominal cavity. The extraembryonic body cavity within the umbilical cord was closed with the return of the intestinal loops. It can be seen that most of the intestinal tube is located outside the abdominal cavity during embryonic development and is connected to the yolk-tip, which is later gradually disassociated from the intestinal tube. Normally, the digestive tract is not connected to the umbilicus after birth; if there are different degrees of residual structures in the development process, the corresponding symptoms will appear, some of which are manifested in the umbilicus “water”. Common pathologic anomalies include: umbilical velvet, umbilical sinus, umbilical fistula, yolk duct cyst, Meckel’s diverticulum, and umbilical intestinal fascicle. Umbilical velvet and umbilical sinus due to the umbilical residual mucosa, local mucus secretion, the child’s underwear is always infiltrated with dirt; umbilical enterocutaneous fistula due to the umbilicus and intestinal tubes between a fistula connected to the umbilicus, the umbilicus constantly yellow intestinal contents out of the flow, the amount of more. Another cause of umbilical “water” disease is the umbilical ureter anomaly. Normal children born after the umbilical ureter has degeneration atresia; if the embryonic period of the umbilical ureter is not degeneration atresia, after birth umbilical cord and bladder have a pipe connected, called umbilical ureteric fistula. Umbilical ureteric fistula is often manifested as umbilical leakage. If both ends are occluded and a lumen remains in the middle, an umbilical ureteric cyst is formed, and if one end is atretic, an umbilical sinus is formed. Imaging and ultrasound can be diagnostic. Therefore, when the child’s umbilicus continues to “flow”, parents should pay attention to, should promptly consult a doctor.