There are some who believe that one of the potential side effects of rapid weight loss (not necessarily the MC itself) is the formation of gallstones. In the case of concerns with gallstones I would recommend you consult a trusted health care professional prior to starting the diet.

Kidney stones are much easier to flush out because the stone may be in the urine stream. The force of the moving urine can force them out. Unfortunately the gall bladder does not work this way, there is no forceful flow at all. When you eat a meal with fat, hormones signal the gallbladder to simply contract. This will empty the bile into the first part of the small intestine, through an orifice the diameter of a pencil lead. Gallstones have a hard time passing through an orfice of this size and are very reluctant to leave the gallbladder, they can be as large the size of a marble. So it's unlikely that the MC or any kind of flush will cause them to pass.

Are you sure you have gallstones, have you had an ultrasound or a positive diagnosis?

Hope this helps.

...vegeman