Hi, Welcome to Health care magic forum.
As you describe, it appears to be the
hernia, near the belly button.the other causes may be the gastric hyper acidity,
adhesion etc.
I advise you to consult a surgeon for diagnosis and treatment.
You may need to have M.R.I. and other tests for confirmation.
Usually it needs surgery for release of the hernia, or adhesion.
Take more of green leafy vegetables, pulses, sprouts, and protein rich foods, to have good recovery, and resistance against infections.
Wishing for a quick and complete recovery. Thank you.