Why don't you ask Andreas about the stomach pain, Boyz? I really do not know, sorry.
I remember what he said about stopping the Liver Flush before all the stones are gone. When we have stones in the liver, the liver accomodates them and adjusts to them. When we flush some of them out, this stirs things up in the liver.
All of a sudden the toxic stones that are left move in the liver, and it has to readjust. This can cause illness and pain. In this way it is worse to do a partial flushing than never to start at all, I understand. I believe you should keep flushing to finish up the good work you have started. Your liver will be so happy!!