I get the logic of "where do these stones come from??" But I have the same reaction (the wonderment) with every colonic irrigation. Where the heck does all this sludge come from?
I believe as long as the stones are coming out, they're coming out of the liver (as opposed to them being formed by the oil of the flush potion, etc.); also, who knows what makes each individuals stones? You get bunch out, but slowly the collection builds up again. Fortunately, it sounds like we can get ahead of stone production with flushing and careful diet.