I know this thread is a little old, but here's my $.02:
Pick up Udo Erasmus's book Fats that Heal Fats that Kill. It explains the benefits of flax better than what any of us can summarize here. I found it cheap used on Amazon.
Here's what I do: I alternate ground flax with psyllium and a product called Super Seed Beyond Fiber from Garden of Life. Another good fiber supplement is Colonix Internal Cleanser from www.drnatura.com. I alternate just to make sure that I don't get any kind of dependency on a particular type/product.
I personally don't take OTC fibers, especially citrucel. The fiber type in citrucel has shown to do nothing about aiding cholesterol elimination (just pure cellulose, I believe). The fiber found in flax, okra, and apple pectin has shown to be very good at getting rid of excess intestinal cholesterol. Flax, psyllium, apple and grapefruit fibers aren't expensive (cheaper than OTC, I've found).
I was diagnosed with diverticulosis last year (the pain of diverticulitis is not fun, trust me) and I decided to take intestinal health much more seriously. Either that or end up with a colostomy. Screw that.
Despite what some people may think, flax seeds are not a danger to people with this condition (at least not according to the Mayo Clinic). Some seeds and nuts should be avoided, but for the most part it's ok to eat just about anything. Just go look for diverticulitis on the Mayo Clinic website if you want to read more about that.
Your lady should get at least 25 grams of fiber per day. The fats present in ground flax will not make her fat, and will aid in ease of elimination and improving her skin. Plus, the mucilage in flax is a great benefit as it has shown to be a gentle laxative.
Just buy the whole seeds and grind them when needed, to keep it as fresh as possible. I bought a Krups coffee grinder for less than $20 and it rocks. I just throw a tablespoon of flax into it, grind for a few seconds then throw them into my shakes (just not the PWO shakes) and into yogurt.