Thank you for the lead. I called the number above and spoke to a pathologist. After looking into the issue, he replied:
"I have spoken to one of the medical directors as well as to a few of the technologists that perform the testing. The method that we use is Reflectance Fourier Transform Infrared Spectroscopy (FTIR)/Polarizing Microscopy. It allows us to identify the components of the stone and conclude that the components are or are not consistent with a gallstone. Those components include cholesterol, Bile salts and bile pigments. I am having the lab pull a sample FTIR spectroscopy and a sample report. If you have a fax number I can send them to you tomorrow."
The question is whether this is sufficient to resolve the issue. I would appreciate input from those of you who are technically inclined and want to participate. I would also like the reference to the Lancet paper that we will be refuting so that we can enlist their help in constructing an experimental design. They have a research department.