I am not sure WHAT it is, but I do know it works. I think it is the husks (bran) of a kind of seed which is entirely fibre. It is the major ingredient of Metamucil.

Strangely enough, it is the treatment for BOTH constipation AND diarrhea. In the first, the fiber helps the body move the material on through. In the second, the fiber absorbs excess water, creating a more solid waste material.

Personally, I'd rather take the capsules than drink that stuff, even the sugar free version which has aspartame. Who needs extra artificial sweetener?

Go visit the threads above.