I found this article because the 'news' articles said IBS could be substantially improved by vitamin D supplements. However, the actual science says that IBS sufferers have low vitamin D levels and should get supplemented and that may (may) have an impact on quality of life (surveyed the participants, and there was a marked increase in the QOL scores given by participants).

It lacked scientific rigor because they were unable to find a sample of IBS patients who weren't low in vitamin D (they were all deficient) That being said, it may still worthwhile to take the supplements because if you're like me, you avoid milk like the plague so where is your vitamin D coming from?

In my own anecdotal point of view, my IBS symptoms started when I stopped drinking milk in my mid teens, but I am not controlling for all variables.so, I will try supplements. I use a daily multivitamin now, but maybe up the D?