1. Neonatal umbilicus Because the umbilicus is not long broken, there are local “wounds” and necrotic stumps that have not yet fully healed, and the newborn’s own immunity is not yet mature and resistance is poor, so germs can take advantage of the opportunity to invade and cause a purulent infection – umbilicus. The most common is a small amount of purulent or mucus discharge after the umbilical cord has fallen off, and the surrounding skin is slightly red, not swollen, and not obviously painful to the touch. The child has systemic manifestations such as crying, fever, decreased appetite, and increased white blood cell count. If these children are not treated promptly, sepsis or peritonitis may occur. Treatment: Keep the area clean and dry and antibiotic treatment. Under normal circumstances, the yolk duct and other structures are either occluded, fibrotic, or disappear during fetal development and after the umbilical cord is broken, leaving only a skin scar depression – the umbilicus. Umbilical velvet is a polyp-like growth that appears in the umbilicus of a child after the yolk duct is occluded and its distal mucosa (intestinal mucosa) has not completely disappeared. A cherry-red, smooth and moist polyp-like growth appears on the trabecular surface and may have a small amount of “pus”-like discharge, which may bleed if rubbed locally. Treatment: Generally, 10% silver nitrate cautery is available for rice-grain umbilical velvet; the tip-like umbilical velvet is first ligated with thread, and the residual part is then cauterized with 10% silver nitrate. The thick umbilical cord velvet mostly requires surgery, which is relatively simple. The umbilical sinus also originates from the remnant tissue of the embryonic yolk tube. There is a fistula in the umbilicus with a blind end, and the clinical presentation is similar to that of the umbilical velum. Treatment: surgical treatment. 4, umbilical intestinal fistula After birth, because the yolk duct is not closed, there is a fistula in the umbilicus connected to the small intestine, mostly accompanied by small intestine Michael’s diverticulum. Clinical manifestations umbilical secretions more, even fecal water-like liquid to the umbilical outflow. The diagnosis is confirmed by contrast into the small intestine on umbilical angiography. Treatment: Surgical treatment after the diagnosis is confirmed. 5. Umbilical ureteral fistula After birth, the umbilical ureter is connected to the bladder because the umbilical ureter is not closed. The umbilicus has more clear ooze, especially when the child is crying and urinating. The diagnosis is confirmed by contrast into the bladder on imaging. Treatment: Surgical treatment after the diagnosis is confirmed.