Infectious gastroenteritis (IGE) has been linked to the development of several chronic health conditions, including irritable bowel syndrome (IBS). Recently, it has been proposed that IGE is also linked to the onset of inflammatory bowel disease (IBD). A human study evaluated 3019 cases of IBD from U.S. Armed Forces medical data and found that a previous diagnosis of IGE significantly increased the odds of IBD and that a previous diagnosis of IBS increased risk for IBD by approximately 5-fold over no such previous diagnosis. This study supports the idea that IGE may contribute to the development of IBD in susceptible people via disruption of normal gastrointestinal homeostasis.

This study in military personnel reveals a correlation between infectious diarrhea and subsequent development of IBD. This is perhaps not surprising because the pathogenesis of IBD in humans is so complex, involving environmental, microbial, genetic, and immune factors. Similar complexities have been proposed for dogs and cats, and one cannot help but wonder whether a parallel exists. I have certainly seen several cases of IBD develop in dogs after elimination of Giardia infection, which can break down the tight junctions between intestinal epithelial cells to expose the submucosa to luminal antigen. Does the same thing happen after recovery from other intestinal parasitic, bacterial, or viral infections? What does this sort of intestinal damage and inflammation do to the intestinal flora? Do bacterial populations change? This is certainly food for thought.

Infectious gastroenteritis and risk of developing inflammatory bowel disease. Porter CK, Tribble DR, Aliaga PA, et al. GASTROENTEROLOGY 135:781-786, 2008.