Make sure you are getting close to 30g of insoluble fiber. That is the good stuff that cleans you out. Soluble is what things like benefiber consists of and it just turns into a goo that doesn't really aid in cleansing but more of stabilizing blood sugar and other things.

Metamucil is insoluble. Benefiber is soluble.

We want the good rough stuff.

A good fiber supplement:
http://www.vitacost.com/Yerba-Prima-Daily-Fiber-Formula