Appendectomy is followed by increased risk of Crohn's disease

Gastroenterology. 2003 Jan;124(1):40-6. doi: 10.1053/gast.2003.50021.


Background & aims: Appendectomy is associated with a low risk of subsequent ulcerative colitis. This study analyzes the risk of Crohn's disease after appendectomy.

Methods: We followed-up 212,218 patients with appendectomy before age 50 years and a cohort of matched controls, identified from the Swedish Inpatient Register and the nationwide Census, for any subsequent diagnosis of Crohn's disease.

Results: An increased risk of Crohn's disease was found for more than 20 years after appendectomy, with incidence rate ratio 2.11 (95% confidence interval [CI], 1.21-3.79) after perforated appendicitis, 1.85 (95% CI, 1.10-3.18) after nonspecific abdominal pain, 2.15 (95% CI, 1.25-3.80) after mesenteric lymphadenitis, 2.52 (95% CI, 1.43-4.63) after other diagnoses. After nonperforated appendicitis, there was an increased risk among women but not among men (incidence rate ratio 1.37; 95% CI, 1.03-1.85, respectively, 0.89, 95% CI, 0.64-1.24). Patients operated on before age 10 years had a low risk (incidence rate ratio 0.48, 95% CI, 0.23-0.97). Crohn's disease patients with a history of perforated appendicitis had a worse prognosis.

Conclusions: Appendectomy is associated with an increased risk of Crohn's disease that is dependent on the patient's sex, age, and the diagnosis at operation. The pattern of associations suggests a biologic cause.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Age Distribution
  • Appendectomy / adverse effects*
  • Appendectomy / statistics & numerical data
  • Child
  • Child, Preschool
  • Cohort Studies
  • Control Groups
  • Crohn Disease / epidemiology
  • Crohn Disease / etiology*
  • Crohn Disease / physiopathology
  • Female
  • Humans
  • Incidence
  • Infant
  • Infant, Newborn
  • Male
  • Middle Aged
  • Prognosis
  • Risk Assessment
  • Sex Factors