I am not a medical expert, but I will say this. I have passed stones without Epsom Salts (As have many others). I have used the same protocol and gotten no stones, some stones or many stones. Logic tells me that my results are not just a matter of coagulated bile or olive oil.
Also, doctors tell us that getting rid of stones without surgery is impossible. They claim stones can not pass out of the GB. They have no frame of reference for a procedure they don't do.So how is it that your mother knows that passing a tiny stone is excruciatingly painful? Is she referring to kidney stones? Remember (as someone on this site once pointed out) a 6-10 pound baby can come out of a rather small openning. It's not so hard to believe that the common bile duct can dialate to accomodate a 1/4" stone.
This is just my lay opinion, but I hope it is helpful.