A red belly button with discharge that also smells bad may be due to an umbilical infection, trauma or mosquito bites, and an unclosed umbilical ureter or umbilical intestinal canal. 1. Umbilicitis: umbilical nest deeper and more skin folds, usually do not pay attention to hygiene, it is easy to form dirt; or dirty hands repeatedly rubbed the navel many times, the umbilical cord inflammation, causing local redness, there will be redness and swelling and ulceration, foul-smelling liquid outflow. If the symptoms are not too serious, you can apply local povidone-iodine, prohibit contact with water during the period, abstain from alcohol, spicy and stimulating food, if the local infection is serious, it is recommended to be treated under the guidance of a doctor. 2. Trauma or mosquito bites: generally have this situation, need to go to the surgical consultation, the first local debridement. 3. Unclosed umbilical ureter or umbilical canal: If necessary, imaging tests may be needed to clarify whether there is an unclosed umbilical ureter or umbilical canal. Surgery may also be considered as an option after the inflammation has resolved. Appear belly button red and accompanied by odor should go to the hospital in a timely manner to identify the cause of the disease, targeted treatment, do not self-medication.