Actually, you have a few possibilities here, but I'm going to direct you to go to a good acupuncturist (particularly one which deals with herbs). What you may be dealing with here is a general weakening of some of your systems. This first shows up in your gallbladder and kidneys, but stomach and pancreas issues sometimes arise thereafter. (I don't know the specifics, but it has to do with what they consider lack of heat in certain regions. Stones are usually the result of a "diseased" or "weak" organ.)
Can you be having gallstones? Possibly. Another possibility is biliary dyskinesia, which would indicate a weakening of the gallbladder for one reason or another.
You might also want to see a chiropractor. (Though I wouldn't recommend an acupuncturist who is also a chiropractor: they seem not to be as good as those who stick to one area.) A lot of problems like this arise form issues with subluxations in the celiac plexus region of the back. When those nerves are affected, many of your internal organs are.
Good luck with this, and sorry I could not be more specific.