title: Tonsillectomy and inflammatory bowel disease: a meta-analysis.
abstract: OBJECTIVE
  The pathogenesis of inflammatory bowel diseases remains unclear. Genetic and environmental factors are involved. Studies of the association between tonsillectomy and inflammatory bowel disease have yielded conflicting results.
  
  
  METHODS
  PubMed and EMBASE were searched to identify studies evaluating the association between tonsillectomy and inflammatory bowel disease [Crohn's disease (CD) and ulcerative colitis (UC)]. Odds ratios with 95% CI were calculated using a random- or fixed-effects model. The χ(2) test and I(2) test were used to assess homogeneity. Egger's test was used to evaluate publication bias.
  
  
  RESULTS
  Thirteen observational case-control studies including 4122 patients (3035 UC/1087 CD) and 5103 controls were analysed. The summary odds ratio estimated for UC following a tonsillectomy was 0.932, 95% CI 0.819-1.062. The odds ratio for CD following a tonsillectomy was 1.194, 95% CI 0.992-1.437. Publication bias was not detected (Egger's test coefficient -3.50 to 1.55; P = 0.39).
  
  
  CONCLUSIONS
  No obvious association between tonsillectomy and inflammatory bowel disease was identified in our meta-analysis.
authors.affiliation: Department of Gastroenterology, First Affiliated Hospital, Nanchang University, Nanchang, Jiangxi Province, China.
authors.forename: H-F
authors.initials: HF
authors.lastname: Xiong
authors.affiliation: Department of Gastroenterology, First Affiliated Hospital, Nanchang University, Nanchang, Jiangxi Province, China.
authors.forename: B
authors.initials: B
authors.lastname: Wang
authors.affiliation: First School of Clinical Medicine, Lanzhou University, Lanzhou, Gansu Province, China.
authors.forename: Z-H
authors.initials: ZH
authors.lastname: Zhao
authors.affiliation: Department of Gastroenterology, First Affiliated Hospital, Nanchang University, Nanchang, Jiangxi Province, China.
authors.forename: J
authors.initials: J
authors.lastname: Hong
authors.affiliation: Department of Gastroenterology, First Affiliated Hospital, Nanchang University, Nanchang, Jiangxi Province, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: Department of Gastroenterology, First Affiliated Hospital, Nanchang University, Nanchang, Jiangxi Province, China.
authors.forename: X
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Department of Gastroenterology, First Affiliated Hospital, Nanchang University, Nanchang, Jiangxi Province, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Xie
mesh_terms: D016022:Case-Control Studies; D016009:Chi-Square Distribution; D003093:Colitis, Ulcerative / Q000209:etiology*; D003424:Crohn Disease / Q000209:etiology*; D006801:Humans; D064887:Observational Studies as Topic; D016017:Odds Ratio; D012307:Risk Factors; D014068:Tonsillectomy / Q000009:adverse effects*
keywords: Crohn's disease; Inflammatory bowel disease; environment; tonsillectomy; ulcerative colitis