There are a couple of reasons this can happen. One is that regardless of whether or not you have pouchitis or bacterial overgrowth, antibiotics can thicken the stool, and that by itself can be a big, big relief when you have chronic diarrhea. This happens because a large part of feces is bacteria. Kill bacteria, and you have less bulk.
Another reason is that antibiotics are used for treating Crohn's and even UC sometimes. The thinking I believe is that IBD can be an inappropriate inflammatory response to bacteria (or a virus in some cases) that runs amok. Antibiotics may help disrupt that cycle.
And why would your cuffitis stay in remission now off antibiotics when it did not before? Well, the nature of IBD is relapse and remission that is unpredictable. Sometimes remission is just spontaneous, no matter what you do. Maybe in your case the bacteria was supressed long enough that was all that was needed.
But, just when you think you have it all figured out, here comes the next relapse, so who knows?
Jan
