First of all, that article was wrong about quite a few things, including the process of a liver flush.
Regardless of WHERE the stones come from, people report great results after the flush.
I don't see anything dangerous about a flush if done properly. The worst that could happen is an overdose on Epsom Salts , or doing the flush properly and having a gallbladder attack when trying to pass a stone.
I guess you don't believe people can pass parasites in their stool either. Perhaps you also believe that the only people who are infected with parasites are in third world countries?