The cause of a very smelly belly button with odor is mainly due to a belly button infection, commonly known as umbilicitis. The cause of navel infection is often caused by not paying attention to navel hygiene, often scratching the navel with dirty hands, or not paying attention in the shower causing dirty water to enter the navel, which in turn causes navel infection, resulting in a smelly navel with odor. To treat umbilical cord infection, you need to go to a hospital for general surgery and have an ultrasound examination of the navel to clarify. You need to flush the navel with saline and metronidazole, flush the navel with secretions, disinfect the wound with iodophor, wrap it with sterile gauze, and change the medication every 2-3 days or so to observe the changes in the wound. At the same time, it is necessary to take anti-inflammatory drugs with it. Cephalosporins can be chosen, but it should be noted that alcohol should not be consumed during taking cephalosporins to avoid disulfiram-like reactions, etc. At the same time, good hygiene habits should be practiced to avoid the recurrence of belly button inflammation.