The first of these is a fistula, which is a fistula between the belly button and the intestinal tract, which is caused by a residual fistula between the belly button and the intestinal tract. 3, umbilical urinary fistula, between the navel and the bladder, the umbilical ureter has not degenerated and the fistula remains, when the pressure in the bladder increases, urine can pass through the fistula and overflow from the umbilicus. It is recommended to visit the hospital for surgery, perform a physical examination and, if necessary, CT and ultrasound examinations near the navel to clarify the diagnosis.