I think the burning has to do with toxins also. I have only done two liver flushes. The burning was almost unbearable with the first one. With the second one, there was no burning at all. I did them two months apart, and the only difference is that I took malic acid for about 3 weeks before the first one because I kept putting off the flush, and only one week before the second. Also, I started taking liver herbs (Milk Thistle, and a formula by Nature's Way called, "AKN") and drank Watermelon Seed Tea for the kidneys after the first flush because it released a lot of toxins into my body. I had fatigue and skin eruptions. The second flush yielded fewer, smaller green stones and sludge. There was no fatigue, less severe skin eruption. So I think the burning is toxins.