title: Appendectomy in adulthood and the risk of inflammatory bowel diseases.
abstract: BACKGROUND
  There is controversy as to whether appendectomy protects against the development of ulcerative colitis, but the possible impact of appendectomies performed in adulthood has not been systematically investigated.
  
  
  METHODS
  We conducted a large case-control study based on inpatient records from Veterans Affairs hospitals in the United States for the period 1969-96. We identified 6,172 male patients with ulcerative colitis (age range 19-101 years, mean 57.4 years) and 4,498 male patients with Crohn disease (age range 18-99 years, mean 52.9 years). Each of these case patients was individually age- and race-matched to five other male veterans without recorded history of inflammatory bowel disease. We compared records of prior appendectomies in adulthood for the matched case-control sets using conditional logistic regression.
  
  
  RESULTS
  Overall, both ulcerative colitis (odds ratio (OR) = 1.6, 95% confidence interval (CI): 1.3-2.1) and Crohn disease (OR = 2.5, 95% CI: 2.0-3.3) were significantly and positively associated with history of appendectomy in adulthood. However, risks were not increased at intervals of 15 years or more between appendectomy and inflammatory bowel disease (ulcerative colitis: OR = 0.9, 95% CI: 0.4-2.1; Crohn disease: OR = 1.2. 95% CI: 0.5-2.5).
  
  
  CONCLUSIONS
  The elevated risk of inflammatory bowel disease, notably Crohn disease, after appendectomy probably reflects differential diagnostic difficulties in patients with abdominal pain. Appendectomy carried out during adulthood seems not to confer protection against ulcerative colitis.
authors.affiliation: Dept. of Epidemiology Research, Danish Epidemiology Science Center, Statens Serum Institute, Copenhagen. mfr@ssi.dk
authors.forename: M
authors.initials: M
authors.lastname: Frisch
authors.forename: G
authors.initials: G
authors.lastname: Gridley
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001062:Appendectomy / Q000009:adverse effects*; D016022:Case-Control Studies; D003093:Colitis, Ulcerative / Q000209:etiology* / Q000517:prevention & control; D003424:Crohn Disease / Q000209:etiology* / Q000517:prevention & control; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D012189:Retrospective Studies; D012307:Risk Factors