I don't have it.... but I have many family and friends who do. I do not profess to know much about it at all... and what I offer here is purely anecdotal... but never the less it's quite accurate from my experience.
Most manage it following doctor's orders and like Greg's sister do quite well... even great.
A few I've known do not, and without exception, (my family and friends, not speaking for the public at large), they suffer problems. Truly a lifestyle choice, and from what my family members who have it tell me... following doctor's orders is not a burden in the least. - Jimmy