Some flushes show a false negative (you flush and no stones come out). I would make sure your drinking enough olive oil as some other posts have stated that sometimes 1/2 cup olive isnt enough for them to produce stones everytime. Im on my fourth flush now and I have gotten stones out everytime. I didnt have nausea my first flush but the second and third I got alot of nausea-some degree of that seems a little normal. Also try eating a fatty meal for dinner the night before (stimulating bile production) and then dont eat any fat for breakfast or lunch (store up bile in GB and increase pressure there). Personally Ive noticed an increase in energy 2-3 days after every flush, its great, so dont give up. O and by the way taking fiber after your done with the Epsom Salts also helps me minimize the released toxins and a sick feeling after flushes. Good to you!