Post-infectious irritable bowel syndrome: Mechanistic insights into chronic disturbances following enteric infection

Abstract

Irritable bowel syndrome (IBS) is a commonly encountered chronic functional gastrointestinal (GI) disorder. Approximately 10% of IBS patients can trace the onset of their symptoms to a previous a bout of infectious dysentery. The appearance of new IBS symptoms following an infectious event is defined as post-infectious-IBS. Indeed, with the World Health Organization estimating between 2 and 4 billion cases annually, infectious diarrheal disease represents an incredible international healthcare burden. Additionally, compounding evidence suggests many commonly encountered enteropathogens as unique triggers behind IBS symptom generation and underlying pathophysiological features. A growing body of work provides evidence supporting a role for pathogen-mediated modifications in the resident intestinal microbiota, epithelial barrier integrity, effector cell functions, and innate and adaptive immune features, all proposed physiological manifestations that can underlie GI abnormalities in IBS. Enteric pathogens must employ a vast array of machinery to evade host protective immune mechanisms, and illicit successful infections. Consequently, the impact of infectious events on host physiology can be multidimensional in terms of anatomical location, functional scope, and duration. This review offers a unique discussion of the mechanisms employed by many commonly encountered enteric pathogens that cause acute disease, but may also lead to the establishment of chronic GI dysfunction compatible with IBS.

Keywords: Post-infectious irritable bowel syndrome; Infectious diarrhea; Enteric pathogen; Inflammatory disorders; Immune alterations

Core tip: This review discusses the long-term consequences of acute enteric infections that may serve to trigger post-infectious irritable bowel syndrome, a routinely diagnosed disorder. This unique discussion elucidates novel initiation mechanisms, underlying pathophysiological features of post-infectious irritable bowel syndrome, employed by commonly encountered enteric pathogens.