i eat a ton of fiber, at least 50g per day.
i recall reading some interesting info on fiber awhile back, it was in some harvard medical study. it said that all fiber isnt the same, that insoluable fiber works soley by mechanical action. that means that the only important part of fiber is the particulate size. many sources of fiber, especially fiber supplements have very fine ground up fiber. this renders the fiber completely useless!!!!! it doesnt matter how much of it you eat if it from uselss ground up fiber. the test was performed with subjects eating a wide range of fibers with different particulate sizes and feeding another group plastic pellets of the same size. the bowel funtions of group with similar particle sizes were identical. since we all know plastic pellets have absolutely no chemical interaction, they proved fiber works soley by mechanical action. the study was obviously more in depth, i am citing what i know from memory.
so for most of you who didnt read all my rambling, fiber is useless if its ground up into fine power.