YESSSSSSSSSSSSS.
I used to struggle to get in 25 grams, now I'm eating about 50 without even trying and if I don't drink TONS of water I get constipated and can pack on 3 lbs over night. especially if I eat black beans which I eat a lot of. I have been sick and (badly) haven't been drinking as much as I should and yet HAVE been eating LOTS of fiber. I had to take a laxative last night and I lost 3 lbs by morning...OMG!
make sure you drink plenty of water with fiber. I try and drink 96 oz since I'm eating so much but it doesn' always happen and when it doesn't, I feel the effects.