julie - 40 grams of fiber does seem like way too much. personally, i always had bad experiences with fiber supplements. it made things too hard and bulky. i guess you just need to experiment with the fiber and see how much you can handle and still stay comfortably regular.
i'd start with 1 or 2 tablespoons of MOM. it's kind of another thing you need to play around with to see what suits you and keeps you comfortable. i can't imagine your surgeon advising you against using it, most drs from what i've seen and heard, seem to like it. good luck!