Hiwelcome to HCMForum. what you had above the belly button is an abscess
having some organism ,at some point it bursts and evacuate almost all the pus. A milli fraction of the pus left undrained is with bacteria, and they start growing when grow enough to cause infection it flares and cause infection to form an abscess again.
I advise you to consult a surgeon for diagnosis and treatment. with drainage
medicines also should be given. Thanks for calling.