I have back pain - across the small of my back. I associate it with IBS because it occurs mostly on the days I have a "bad stomach day" like this morning. I think that my muscles get weak from sitting on the porcelain throne, either that or all the spasming. Who knows. It may not be associated at all but it seems like it is to me.As an aside, I ate two altoids and am already feeling much better. Go figure.