Maybe I can answer this. People often call the gallbladder flush a LIVER flush, when in reality it is flushing the gallbladder and the bile ducts. Remember the bile is produced in the liver and stored in the gallbladder. Due to chemical signals the gallbladder contracts and forces the bile out and toward the intestine so that it can be used to digest foods in the intestine. There are several types of these bile ducts (as a group they are called the hepatobiliary ducts): the hepatic duct, the cystic duct, and the common bile duct. [I'm not even getting into the pancreatic duct!] I think that stones are primarily formed in the gallbladder, but then some can get pushed along and can lodge in the ducts. Because the liver produces the bile originally, people often call this a Liver Flush and refer to the stones as liver stones .. probably because the liver is the beginning of this 'bile system.'
Now I'm not telling you that there are no such thing as liver stones (intrahepatic calculi), but these are very rare in the West. For some reason they do appear more in the Far Eastern countries. Their cause is unkown but some think it is a defect in the way the liver processes cholesterol.
So I'm guessing that your doctor friend has not seen intrahepatic calculi - though they do exist - because she's a Western doctor. However, I'm sure she's seen Gallstones (both in the gallbladder and in those bile ducts)!
Hope this information helps...