Swelling around the umbilicus, oozing with a foul odor, which may be purulent or mixed with blood are symptoms of the clinical diagnosis of umbiliculitis. Umbiliculitis is a bacterial infection of the umbilical stump. Depending on the age of onset, there are adult umbiliculitis and neonatal umbiliculitis, and there are acute umbiliculitis and chronic umbiliculitis (2 types) according to the pathological process. Acute umbiliculitis is an acute cellulitis of the periumbilical tissues, which can be complicated by abdominal wall cellulitis if the infection progresses, and may develop into a periumbilical abscess, with the risk of peritonitis and sepsis. The pathogenic bacteria are Staphylococcus aureus and others. Chronic umbiliculitis is a chronic inflammatory manifestation of the umbilicus caused by irregular treatment of acute umbiliculitis, prolonged treatment or local irritation of the unhealed trauma and foreign body left after the umbilical cord has fallen off in newborns. So, what is the differential diagnosis of periumbilical swelling? The following is a brief introduction. Differential diagnosis of periumbilical swelling 1. umbilical sinus: caused by the unclosed umbilical end of the yolk duct. 2, umbilical intestinal fistula (yolk duct unclosed): a round raised bright red mucous membrane is visible at the umbilical orifice with a fistula opening in the middle, with foul-smelling discharge or liquid fecal discharge, and the diagnosis can be confirmed by X-ray examination with oral charcoal powder or injection of contrast agent in the umbilical orifice. Surgical treatment is required. 3. Umbilical ureteral fistula (unclosed umbilical ureter): there is often clear fluid flow from the umbilicus, local injection of contrast agent can enter the bladder or retrograde contrast of the bladder can reach the skin, and injection of methylene blue shows blue urine discharge from the umbilicus. Surgical treatment is required.