Magnesium supplements can also cause stomach irritation- I just asked my GI doctor about it today, and he said, yes, it can, and no, there is nothing you can do about it except take it with a good sized meal (I had a -now <img src="i/expressions/face-icon-small-smile.gif" border="0"> ! - unusual stomach ache yesterday, and I just started the slomag a few days ago <img src="i/expressions/face-icon-small-wink.gif" border="0"> ).