Gastrointestinal infections and the development of irritable bowel syndrome

Approximately 10% of the millions of persons with functional gastrointestinal disorders (FGDs) including irritable bowel syndrome (IBS) had their illness onset following an acute bout of infectious diarrhea and are referred to as having postinfectious (PI) FGD or PI-IBS. Recent studies have helped to identify the pathogenesis and natural history of these disorders.

Groups of patients with acute diarrhea or dysentery (passage of grossly bloody stools) are being followed for development of PI-IBS. Persistent mucosal inflammation, air trapping in the gut, and alteration of intestinal motility contribute to the disease symptoms in genetically susceptible persons. The prognosis of postinfectious forms of IBS is more favorable compared with people with idiopathic forms of the disorder.

With full characterization of postdiarrhea forms of FGDs, we should be able to define the mechanisms of disease early in the course of chronic illness and to better understand the more common idiopathic forms of the disease. We are likely to identify specific alteration of gut pathophysiology in postinfectious FGDs and to then classify them not as a poorly characterized group of functional disorders but as specific gastrointestinal disorders.