We have seen how budesonide can restore normal collagen layer thickness. A remarkably similar effect occurs when the faecal stream is diverted by ileostomy.
Another study of a patient with severe collagenous colitis confirms that temporary faecal stream diversion restores the mucosal structure but relapses after the ileostomy is reversed. The authors hypothesise that a luminal toxic agent triggers the onset of CC
We now look at the possibility that bile acid could be a noxious factor.