*shrugs* You can find anything to prove anything. For me, I had really painful constipation eating high fiber (from grains) and I have smooth, pleasant poos eating high fat and with moderate amounts of leafy green vegetables.
I think modern science and medicine has really no clue what is going on with people's bodies, so I eat the way that makes MY body feel good. For me, that has been proven to be low carb, no grain, high fat, moderate protein.
This is my illustration as to how fiber works for me:
fiber by coyotevick, on Flickr