Irritable Bowel Syndrome (IBS) Support Group
Irritable bowel syndrome is a common intestinal disorder that is characterized by bloating, abdominal pain, diarrhea, cramping, and constipation. Typically no abnormalities appear during standard medical testing, and so irritable bowel syndrome is identified by the symptoms. Although irritable bowel syndrome can cause serious discomfort, the intestines are not harmed.

I take a statin for my PCS and it has cut down on my chronic diarrhea by a good 80 percent. I also have gas (which I rarely if ever had for the past 13 years since my surgery). When I first started taking it, it almost made me constipated, but I'm not totally sure on that as it has been so long since that happened to me that I'm not too sure that it was what I think it was.
Not sure if that helps on your end, but maybe if you can see how it helps me/has changed my symptoms you might be able to see how it has affected you :)
I don't know a ton about IBS, just I was mis diagnosed with it. While IBS has a diarrhea element, I believe constipation is by far the greater of the two?
If I am taking statins to "cure" my chronic diarrhea (as they bind with bile and make fat breakdown harder) then I would say they could make someone without my issue have greater problems with constipation (and therefore bloating, cramps, etc).
Sorry I wasn't more clear... but I think if I understand IBS correctly then they could reproduce IBS type symptoms.. but again, I can only tell you how they affect me.