I bought a brand called BlueBonnet. It is also capsules, but veggie caps. I take them a little before I start to eat because sometimes the veggie caps can take a while to disintegrate from what I've read. I'm not sure if that is the case from actual experience. I can't remember what fillers it has, but I'd guess the binders and fillers used in tablets would be the same ones as in this, at least that was the impression I remember when I read the label.
Perhaps the diarrhea is related to the effect it is having on the candida. Just a thought. Check the ingredients and compare them to some of your more successful supplements. That way you may be able to pinpoint which ingredient could be causing you problems.