Five-year-old child navel with light yellow discharge can be caused by umbilical infection, umbilical sinus, umbilical polyp and other factors. 1. Umbilical infection: due to poor hygiene of the child’s navel, or because of the umbilical cord itching scratching when the skin is broken, can be secondary to bacterial infection, the local can appear red, swollen, moist performance, can be accompanied by light yellow secretion oozing. 2. Umbilical sinus: the umbilical sinus is a short tube of the yolk duct remaining in the umbilicus, and the umbilicus can be seen as a round mucous membrane bulge, which can be accompanied by light yellow secretion oozing from the local area, and the skin can be accompanied by the change of vesiculation. 3. Umbilical polyp: refers to the intestinal mucosa remaining in the umbilicus, manifested as red polypoid tissue, local secretion of mucus and bloody fluid, combined with the infection can appear light yellow secretion. Five-year-old child navel light yellow discharge, there may be other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.