They told me when I had my gallbladder out, that I could still have stones, in the ducts. While this might be a consideration, have you taken any meds for indigestion? Being careful about what you eat after gallbladder surgery is a wise thing. You gallbladder is gone, so digesting fatty foods and some other things, is going to be tough and could make you sick. Check you diet and make sure it's conducive to not having a gallbladder, Good luck!
Were you prescribed something after the surgery?
This doesn't sound like any Appendicitis.
There might some be sludge in your biliary ducts.
Have you notified your sugeon/GI Specialist about this?