Adults with pus coming out of the navel may be caused by certain diseases, such as umbilical infection, umbilical ureteric cysts, peri-abdominal wall infections, etc., and should seek timely medical attention to identify the cause of the disease. 1. Umbilicitis: adults, especially obese people, the umbilical folds are rich, easy to accumulate water and hide dirt, when scratching and other small trauma caused by the umbilical skin, easy to cause superficial skin infections, resulting in umbilicitis. The main manifestations are redness and swelling of the umbilical fossa and the skin around the umbilicus, accompanied by purulent discharge, itching, pain and other symptoms. 2. Umbilical ureter cysts: refers to the cysts formed during the embryonic growth and development process when the two ends of the umbilical ureter are atretic and the lumen remains in the middle section, patients may have a cystic mass in the middle superficial position of the lower abdomen. When the cyst ruptures or secondary infection, an abscess can be formed and pus flows out, accompanied by fever and other manifestations. 3. Infection around the abdominal wall: Infection around the abdominal wall may invade the umbilical fossa, while the umbilicus is in a lower position, the pus may flow to the umbilical position. Adults with pus coming out of the navel, patients should promptly consult a doctor for a clear diagnosis and targeted treatment by the doctor.