You might well have a stone that is threatening to lodge in the bile duct. If that happen you could trigger sometime much worse that a gallbladder sttack - it is pancreatitus. the blocked duct causes the pancreas to over produce the enzymes amylase and lipase. The overstimulated pancreas becomes inflammed and causes extreme pain and you will require hospitalization to make sure the fragile tissue of the pancreas does not get infected.