Cleaning the bowel using the post flush 2 epsom doses is important. Its true that sometimes stones remain in the colon for months if they are not flushed out and if this part of the flush is skipped.. this is why the 2 epsom doses are so important in the a.m. and shouldn't be skipped. For most of us, this step is sufficient enough.. but if you are older, or have had alot of bowel problems in the past, you might want to look at an occassional colonic just to make sure.