Last year when I was having chest pains and shortness of breath and thought there was a heart problem, (luckily NOT) the docs put me on a cardiac and diabetic diet. I was told NO CAFFEINE Well, after the initial withdrawels I noticed something. I wasn't running to the bathroom as soon as I finished eating anymore. I would normally have a cup of coffee, THEN eat and nearly immediately would have problems. I haven't had that problem since really. Between the better fiber intake AND getting rid of the caffeine, I'm doing MUCH better.
I did have a recent confirmation that it was indeed the caffeine in the coffee when I sneaked having a cup of regular instead of decaf and I was Off to the races....