I don't know what your pain is but I have been experiencing something similar.  I too have acid reflux, also a hiatal hernia, and have had my gall bladder removed.  A year ago, I had upper and lower GI scopes and dilation of my esophagus to help with difficulty swallowing.  Last weekend I experienced a bad pain in my left side, almost like someone had punched me.  Since then I have had one day where I couldn't keep food down, I visited my doctor who did xrays to see if my rib was broken, and results came back normal.  I have had twice since then that I had sharp pain in my left side just below my ribs.  I have also had back pain this week, with no reason to have any kind of injury.  I am sure it is related to my other medical problems.  So hopefully, someone can answer the question for both of us.