A runny belly button with a foul odor is caused by an inflammation of the belly button and an infection of the belly button. Dirty inside the navel secondary to bacterial infection, resulting in inflammation of the navel. Or when cleaning the belly button, accidentally break the skin, not disinfected with iodophor resulting in bacterial infection secondary to inflammation of the broken part. In the early stage, the belly button may be red, swollen, hard and painful, and may become abscessed and have yellow water. Oral antibiotic treatment, such as cefradine, is required, as well as hospital debridement and examination. If there are hard nodes and no abscesses inside the navel, oral antibiotics are sufficient. Use hydrogen peroxide to clean the inside of the navel and clean out the dirt. If there is an abscess forming, the abscess should be cut open and the wound should be drained and changed.