You might have reflux disease ie the reflux of acidic contents in the food pipe from the stomach which causes irritation and pains.
You should also get your calcium checked.
disorders the muscles at the lower end of food pipe which prevents reflux might get weakened and so causes reflux.
You need to consult your doctor and take medications for the antacids and antireflux medicines like domperidone
etc and other prokinetic medicines .
All this after a local inflammtory cause is ruled out which i suppose would have been ruled out , as you had a surgery.
In doubt do reply.