Yes, many people were skeptical, and decided to analyze their stones.
But, unfortunately, not every lab has the equipment to prove that stones are composed of cholesterol, bile, pigment ...
Analysis can only give composition of the stone, it can not prove that a stone came from liver of from gallbladder.
Most stones collected after Liver Flush are formed from bile.
Bile is composed of: cholesterol, bile, pigment, bilirubin, biliverdin, protein , calcium.
Analysis can only prove what stones are composed of.
There is a possibility that stones are formed from bile, but formed inside intestines, not only inside billiary bile ducts.
If results of analysis are: cholesterol, bile, pigment, bilirubin, biliverdin, protein , calcium, then there is no doubt that analyzed stone is indeed made from bile ... but we still don't know where the bile precipitated into stones.
When bile precipitates into stones inside gallbladder or inside bile ducts ... these are then called Gallstones or intrahepatic stones.
When bile precipitates into stones inside intestines ... it may be called feces.
This simple experiment can be used to find out if your stones are formed inside intestines or inside billiary tree: