Magnesium sulphate is commonly used as a laxative. A very effect laxative. Your results may indicate that you need a non-sulphate based magnesium supp. The sulphate may be over kill considering that you already are taking MSM. Excess sulphate can produce a detox reaction that would encourage your bowels to try to dump toxins. Good once in a while, not good for daily use if it is resulting in diarrhea.