Pseudomembranous colitis (clostridium difficile infection)

Pseudomembranous colitis is a type of colon inflammation in which the lining appears to be ‘sloughing’ by virtue of what appear to be membranes on the surface.  These are congealed proteins and cells rather than the actual colon lining.  When visualized with a scope, the lining of the bowel looks red with inflammation but, in addition, one sees whitish plaques on the bowel wall.  These plaques look as though someone had covered the bowel with pieces of cottage cheese.  These whitish plaques look membrane-like when viewed under a microscope.

Pseudomembranous colitis is caused by the bacteria Clostridium difficile.  This bacteria produces a toxin that leads to the inflammatory changes and membranous appearance.  The disorder is more common in patients who have recently had antibiotics, which may have favored the unrestricted growth of this bacteria by eliminating its more friendly bacterial competitors in the colon.  Clindamycin is a commonly-used antibiotic that is known to occasionally lead to pseudomembranous colitis.

Treatment is by antibiotics and is usually straight-forward.  However, pseudomembranous colitis may occasionally become fulminant (very severe and rapidly progressive) and can be bad enough to warrant emergency removal of the colon (colectomy).  While most cases respond to simple antibiotic treatment, there have certainly been many deaths from this disease, particularly in the elderly.  Tests for Clostridium difficile should be carried out in anyone with significant diarrhea or intestinal inflammation, especially if they have been on antibiotics within the past year.

© Pezim Clinic, Vancouver, British Columbia, Canada