Gallstones are small stones that form in the gallbladder or the bile ducts, the tubes that carry bile to the small intestine. They usually don't cause symptoms unless they block the opening to the gallbladder. If that happens, you may have pain in the upper right part of your belly.
If you have a bad attack, or a second attack, you may want to
have your gallbladder removed because you are likely to have more attacks.