Appendectomy and the risk of developing ulcerative colitis or Crohn's disease: results of a large case-control study. South Limburg Inflammatory Bowel Disease Study Group

Gastroenterology. 1997 Aug;113(2):377-82. doi: 10.1053/gast.1997.v113.pm9247453.


Background & aims: Appendectomy has been pointed out as a protective factor for ulcerative colitis (UC). The aim of this study was to elucidate the role of appendectomy in inflammatory bowel disease (IBD).

Methods: Prevalent as well as incident cases with IBD were studied separately using a pairwise age- and sex-matched case-control study design.

Results: In 232 prevalent UC cases, the risk of developing UC was significantly lower after previous appendectomy (odds ratio [OR], 0.36; 95% confidence interval [CI], 0.15-0.80); subgroup analysis found a protective effect only in pancolitis (OR, 0.2; 95% CI, 0.02-0.7). In 208 patients with Crohn's disease (CD), the OR was not significantly increased but a positive association with appendectomy was observed in ileocecal disease. A significant larger proportion of appendectomies was performed close to the time of diagnosis. Smoking was not a confounding factor. No statistically significant associations were observed in incident IBD patients. Prevalent and incident patients taken together resulted in ORs of 0.44 (95% CI, 0.24-0.78) in UC and 1.65 (95% CI, 0.96-2.91) in CD.

Conclusions: An overall protective role of appendectomy for UC was observed. The observations in CD suggest that appendectomy in some cases was a result of still undiagnosed CD.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Appendectomy / standards*
  • Appendectomy / statistics & numerical data
  • Case-Control Studies
  • Colitis, Ulcerative / diagnosis
  • Colitis, Ulcerative / epidemiology*
  • Colitis, Ulcerative / prevention & control
  • Crohn Disease / diagnosis
  • Crohn Disease / epidemiology*
  • Crohn Disease / prevention & control
  • Female
  • Humans
  • Incidence
  • Inflammatory Bowel Diseases / diagnosis
  • Inflammatory Bowel Diseases / epidemiology
  • Inflammatory Bowel Diseases / prevention & control
  • Male
  • Middle Aged
  • Netherlands / epidemiology
  • Prevalence
  • Risk Factors