Thanks so much for your responses --
It seems Benefiber may be the way to go!
I'll call my Mom with that info today.

If anyone has any more thoughts/suggestions on the "burning" issue, I'd be most grateful...It seems this issue comes and goes, in addition to the neck pain, tingling, etc. that so many of you mention.

My Mom mentioned forgetfullness on my Dad's part, too -- I read some of the posts re: "Chemo Brain". My Dad's not had Chemo as yet - is forgetfullness a possible side effect of radiation and surgery as well? (I've read that anesthesia can stay in the body for over a year, and contribute to this kind of issue.)

I can't tell you how much I appreciate your time and energy -- good luck to you as well!