Bitters raise bile levels in the gallbladder and help to stimulate bile release. This helps to prevent stone formation. It also helps with the dissolving of existing gallstones. I know this last claim is controversial, but it is true. Most gallstones form from precipitated cholesterol as the cholesterol levels exceed the saturation point of the bile, which is a "solvent" for the cholesterol. Therefore, increasing the bile in the gallbladder will help to redissolve the cholesterol forming the stones. Lecithin is the component of bile allowing it to dissolve the cholesterol.