Pain in right side uner rib

I have had a pain on the right side under the rib cage for over a year. Recently many tests where done. Colonoscopy was fine. The doc found my galbladder needed to be removed and was on 01/08/08, after surgey doc said liver looked good, lungs looked ggod. I was fine for about a month after that. The pain is back and worse, I can feel a lump in that spot, the pain never goes away.  I went back to the doc they had me do a cleanbse to see if I was backed up, that did not work I was fine, the doc did a CT scan everything is fine, all blood work was fine. Now they want to do an endoscopy, have no idea why as my stomach is not where the pain is. Could it be something from the surgery? scar tissue? Liver? any ideas would be great. I ahve been dealing with this to long

Thank you