title: Eight year prognosis of postinfectious irritable bowel syndrome following waterborne bacterial dysentery.
abstract: BACKGROUND
  Although postinfectious irritable bowel syndrome (PI-IBS) is a well-recognised complication of acute gastroenteritis, its prognosis remains poorly defined. The natural history of PI-IBS was assessed among participants in the Walkerton Health Study (WHS), which has followed the long-term effects of a large outbreak of acute gastroenteritis related to municipal water contamination in May 2000.
  
  
  METHODS
  WHS participants were invited to return for annual assessment at a research clinic. Adult residents of Walkerton at the time of the outbreak who enrolled in 2002/2003 and returned for assessment in 2008 were eligible for a PI-IBS study cohort if they had no prior history of IBS or inflammatory bowel disease. A modified Bowel Disease Questionnaire was used to diagnose IBS by Rome I criteria and to identify IBS subtypes.
  
  
  RESULTS
  Of 4561 WHS participants, 2451 returned for their 8 year assessment and 1166 were eligible for the PI-IBS study cohort (688 females, mean age 46.2 years). The prevalence of IBS among 742 eligible subjects who suffered acute gastroenteritis during the outbreak declined from 28.3% after 2-3 years to 15.4% after 8 years, but remained significantly increased compared with controls who did not have acute gastroenteritis (OR 3.12; 95% CI 1.99 to 5.04). Independent risk factors for PI-IBS at 8 years included female gender, younger age, prior anxiety/depression, and fever or weight loss during the acute enteric illness. IBS subtypes were not stable over time.
  
  
  CONCLUSIONS
  Acute gastroenteritis can trigger IBS symptoms that persist for at least 8 years. Characteristics of the host and the acute enteric illness can predict the long-term risk of PI-IBS.
authors.affiliation: Division of Gastroenterology, McMaster University Medical Centre, 1200 Main Street West, Hamilton, Ontario, Canada. marshllj@mcmaster.ca
authors.forename: John K
authors.initials: JK
authors.lastname: Marshall
authors.forename: Marroon
authors.initials: M
authors.lastname: Thabane
authors.forename: Amit X
authors.initials: AX
authors.lastname: Garg
authors.forename: William F
authors.initials: WF
authors.lastname: Clark
authors.forename: Paul
authors.initials: P
authors.lastname: Moayyedi
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Collins
mesh_terms: D000208:Acute Disease; D000328:Adult; D004196:Disease Outbreaks; D004403:Dysentery / Q000150:complications* / Q000453:epidemiology; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D043183:Irritable Bowel Syndrome / Q000453:epidemiology / Q000382:microbiology*; D008297:Male; D008875:Middle Aged; D009864:Ontario / Q000453:epidemiology; D011379:Prognosis; D014871:Water Microbiology; D014881:Water Supply