About the diarrhea and Atkins diet...

First off, congrats to you both on your weight loss and body fat
reduction.  More power to you!!

I think the problem with the diarrea has to do with, to use a "Zone"
term, the "Bad eicosinoids," discussed in books like, "Enter the Zone,"
and "Beyond Prozac."  The metabolic pathway is complex, but essentially
eating protein stimulates "Good PG's" and carbs stimulate "Bad PG's."
Good PG's can cause diarrhea, bad ones can cause constipation.  Your
wife probably has too many "good PG's."    If  it doesn't botch up the
weight loss too much, she may want to take in a greater percentage of
natural carbs, like fruit and veggies.  If this throws her out of
ketosis, she may want to substitute with a bulking agent, like
Metamucil, which helps absorb water and bulk up the stool so it won't be
so liquidy. (Sorry to be so graphic, but I'm a doctor, and we sort of
get into this stuff!!)  As far as your constipation goes, I don't think
eicosinoids are your problem, because it sounds like you follow a low
carb, low GI diet.  You're probably right in making sure you get enough
fiber.  That ought to keep you "moving."

Best of luck,  let me know how you do.
Caroline, St. Louis, MO