I read in the book, I think it was 'Your Liver Your Lifeline' that different people under the author's care had MRI's performed which detected stones in the gallbladder and liver. They then did the Liver Flush according to his direction. Then they went back and got another MRI. About 90% of the patients evacuated all or most of their stones. About 5% needed to do more flushes to get the rest of their stones. The other 5% had so many stones that were compacted together and or impacted in the ducts that the flush didn't work for them. These "before and after" MRI's are better "proof" the flush actually works then taking the stones to a lab to have them anlysed after they have been removed.
I also read some research somewhere that people who fast are more prone to getting stones then people who don't fast. My take is that the fasts do a tremendous amount of cleansing that gets caught in the liver when the fast is completed. Also, if you have EVER taken any kind of medication or drugs chances are that a good portion of them will still be clogged in the liver. The good news is that you can actually clean them out. A lot of what we take as "medication" the body doesn't recognize and therefore cannot convert to compounds which can be eliminated. Some of these substances get left behind as stones.
I have done countless Liver Flushes and gotten many friends and family into them too. They are much safer then going under the surgeons knife! And much more effective too.