Have you tried Fiber Choice? Here is a great freebie! All you have to do is fill out this form to request your free sample of Fiber Choice! My doctor has requested in the past that I eat high fiber foods. I actually am pretty aware of whether or not I have had much fiber in a day or not. Be sure to sign up and get your coupon before it goes away!
If you have already tried it their website also offers a $2 off coupon from their home page!