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.