yeh i know what you mean about thinkinhg you've won the lottery when you have a normal poop lol. Can't help you with the fiber because i havn't tried it myself yet, but hopefully someone will be along soon.
Have you tried calcium supplements for your D? - alot of people have had sucess with them on here, try looking through some old posts about it...
Also, your other post about colon cleansing, well that's a bit of a contraversial subject on here. Alot of people (myself included) don't think it's a good idea, and by the sounds of it, it was horrific for you - perhaps you could start a new thread with the original post you made, just to show the negative side of it.
Anyway, welcome to the forum, hope you find some answers