Postinfectious Chronic Gut Dysfunction: From Bench to Bedside

INTRODUCTION A signifi cant fraction of the average gastroenterology practice is devoted to the management of functional gastrointestinal disorders, of which the most frequent are irritable bowel syndrome (IBS) and functional dyspepsia. Th ese patients are highly heterogenous, and the lack of a known etiology and wide variability in treatment response makes them particularly challenging to manage. Th e ability to distinguish clear subgroups among these patients may assist in the selection of both shortand long-term treatment options and, potentially, improve treatment outcomes. Th e relationship between infectious gastroenteritis and functional gastrointestinal disorders was fi rst identifi ed over 60 years ago. It has been clear for decades that patients who develop infectious gastroenteritis are at increased risk for functional gastrointestinal disorders. In 1950, Stewart ( 1 ) described “ post-dysenteric colitis, ” a condition he encountered in patients following World War II. He recognized two types of postinfectious colitis: “ type 1, ” did not have an infl ammatory component and improved slowly without treatment; and type 2 postinfectious colitis, which was associated with signifi cant infl ammation and more serious disease. In 1962, Chaudhary and Truelove ( 2 ) described the “ irritable colon syndrome, ” noting in their seminal publication that the syndrome was strongly linked with a history of dysentery. Aft er 2 years, Connell et al. ( 3 ) were the fi rst to identify an organic disorder in patients with postinfectious IBS, observing that motility in response to acetylcholinesterase inhibitor prostigmine, but not basal motility, was greater in patients with postinfectious IBS than in controls. Despite this evidence, the potential relationship between infectious gastroenteritis and functional gastrointestinal disorders was neglected until the past decade. Postinfectious functional dyspepsia is a more recently recognized clinical entity. A 2002 study, conducted by Tack et al. ( 4 ) in 400 consecutive dyspepsia patients with unspecifi ed-onset dyspepsia, found that the initial onset of dyspepsia symptoms occurred aft er a gastrointestinal infection in ~ 17 % of patients. Since these early studies, great strides have been made in our understanding of these disorders, although much remains to be uncovered. Today, postinfectious functional gastrointestinal disorders may be defi ned as the acute onset of new symptoms (IBS or functional dyspepsia) in an individual who has not previously met the Rome criteria for these disorders, immediately following an acute illness characterized by two or more of the following features: fever, vomiting, diarrhea, or a positive bacterial stool culture ( 5 ). It is possible that these patients may form a distinct group separable from patients with unknown etiology; in fact, the disease course Postinfectious Chronic Gut Dysfunction: From Bench to Bedside