ya know what... my first flush produced a bunch of small green nodules that ranged from the size of a bb... to the size of a pea... the second flush produced larger... and each consecutive flush seemed to produce larger ones... so... from that conclusion one could presume that maybe it stretches... maybe the Epsom Salts causes it to relax...
personally i don't care where the stones come from... all i know is the wonderful benefits i receive as a result of flushing...