Adult belly button bleeding is not caused by cancer. The most common cause of adult navel bleeding is acute cellulitis caused by bacterial infection. As some patients are obese, the navel fossa is deeper and there are more folds at the bottom of the navel fossa, in this case there is a tendency to have dirt residue, and if the patient does not pay attention to hygiene normally, or if the skin is abraded when cleaning the dirt, it may cause bacterial infection in the navel fossa. Patients may experience pain, congestion, and edema around the navel fossa, and may also experience bleeding or foul-smelling discharge from the navel, which requires antibiotics for anti-infection treatment and disinfection of the navel to control the infection. If there are other symptoms, further examination in hospital is needed to exclude cancer.