title: Identification of early environmental risk factors for irritable bowel syndrome and dyspepsia.
abstract: BACKGROUND
  The role of childhood environment including exposure to infection via siblings and pets in irritable bowel syndrome (IBS) and dyspepsia is relatively unknown. We assessed proxy measures of microbial exposure in early childhood to assess if these are associated with IBS and functional dyspepsia in later life.
  
  
  METHODS
  Participants (n = 767, response rate = 53%) were a random population sample from Sydney, Australia who previously responded to a validated survey. IBS and functional dyspepsia were defined using Rome III criteria. Early environmental risk factors assessed included type of birth delivery, premature birth, breastfeeding, bedroom sharing, and pet exposure (the latter two then combined as early hygiene factors) up to 5 years of age. Post infectious IBS (PI-IBS) was assessed by development of IBS following gastroenteritis.
  
  
  RESULTS
  In this sample, in adult life 17% developed IBS (of which 20% had PI-IBS) and 12% functional dyspepsia. Development of IBS was associated with childhood factors-a shorter duration of breastfeeding (odds ratios [OR] = 0.87, 95% CI: 0.78-0.97, p = 0.01), sharing a bedroom (OR = 1.89, 95% CI: 1.73-3.08, p = 0.01), exposure to a herbivore pet (OR = 1.65 (1.10, 2.48), p = 0.02), and hygiene factors (OR = 4.39; 95% CI: 1.89-10.21, p = 0.001). The sole factor associated with functional dyspepsia was exposure to a herbivore pet (1.79; 95% CI: 1.19-2.87, p = 0.02).
  
  
  CONCLUSIONS
  Childhood environment factors, particularly bedroom sharing and pet exposure, combined with subsequent risk of microbial exposure are a risk factor for IBS in later life. These associations however need confirmation to rule out any risk of a type I error.
authors.affiliation: Faculty of Health and Medicine, University of Newcastle, Callaghan, NSW, Australia.
authors.forename: N A
authors.initials: NA
authors.lastname: Koloski
authors.affiliation: Department of Psychology, Macquarie University, North Ryde, NSW, Australia.
authors.forename: M
authors.initials: M
authors.lastname: Jones
authors.affiliation: Department of Gastroenterology & Hepatology, Nepean Hospital, Penrith, NSW, Australia.
authors.forename: M
authors.initials: M
authors.lastname: Weltman
authors.affiliation: Department of Gastroenterology & Hepatology, Nepean Hospital, Penrith, NSW, Australia.
authors.forename: J
authors.initials: J
authors.lastname: Kalantar
authors.affiliation: Department of Gastroenterology & Hepatology, Nepean Hospital, Penrith, NSW, Australia.
authors.forename: C
authors.initials: C
authors.lastname: Bone
authors.affiliation: Department of Gastroenterology & Hepatology, Nepean Hospital, Penrith, NSW, Australia.
authors.forename: A
authors.initials: A
authors.lastname: Gowryshankar
authors.affiliation: Faculty of Health and Medicine, University of Newcastle, Callaghan, NSW, Australia.
authors.forename: M M
authors.initials: MM
authors.lastname: Walker
authors.affiliation: Faculty of Health and Medicine, University of Newcastle, Callaghan, NSW, Australia.
authors.forename: N J
authors.initials: NJ
authors.lastname: Talley
mesh_terms: D004415:Dyspepsia / Q000150:complications / Q000453:epidemiology* / Q000382:microbiology*; D005260:Female; D005759:Gastroenteritis / Q000150:complications; D006801:Humans; D043183:Irritable Bowel Syndrome / Q000150:complications / Q000453:epidemiology* / Q000382:microbiology*; D008297:Male; D008875:Middle Aged; D012307:Risk Factors
keywords: childhood infection; environment; functional dyspepsia; irritable bowel syndrome