Sydney Naturopath J. McGuire on the pathophysiology of IBS

Pathophysiology
IBS can develop from a number of different mechanisms. Several have been proposed, including abnormal colonic fermentation or gallbladder motility; altered microbial flora; anxiety/depression; bacterial gastroenteritis; an exaggerated sensory component of the gastrocolonic response; food allergy, intolerance or sensitivity; gastro-oesophageal reflux; impaired transit time or tolerance of intestinal-gas loads; increased gut sensitivity; low-grade mucosal inflammation; motility disorder; myenteric plexus neuronal degeneration; oxytocin-increased thresholds for visceral perception; rectal hypersensitivity; and visceral hypersensitivity.  Irrespective of the mechanism by which IBS develops, symptoms typically relate to altered gut motility, resulting in abnormal transit of gas and stool.