title: Inherited disorders of coagulation appear to protect against inflammatory bowel disease.
abstract: OBJECTIVE
  Crohn's disease and ulcerative colitis seem to be rarely associated with inherited diseases of coagulation. Histological and hematologic studies suggest that thrombotic mesenteric microvascular occlusion is involved in the pathogenesis of inflammatory bowel disease. The aim of this study was to perform a national survey to determine the prevalence of inflammatory bowel disease among patients with inherited disorders of coagulation.
  
  
  METHODS
  Using a postal and telephone questionnaire survey sent to directors of all 129 hemophilia centers in the United Kingdom, the number of patients with inflammatory bowel disease and either hemophilia or von Willebrand's disease was determined. The expected number of cases of inflammatory bowel disease in this population was estimated using published data.
  
  
  RESULTS
  Of 6433 patients with hemophilia and 3129 patients with von Willebrand's disease, 4 cases of Crohn's disease were reported compared with expected 11.97-16.58 cases (standardized morbidity ratio, 0.33-0.24; 95% confidence interval, 0.90-0.01; P < 0.05). Ulcerative colitis also occurred significantly less frequently than expected: 9 observed cases in comparison with expected 19.43-31.35 cases (standardized morbidity ratio, 0.46-0.29; 95% confidence interval, 0.91-0.01; P < 0.025).
  
  
  CONCLUSIONS
  This epidemiological study provides further evidence that thrombosis and vascular occlusion may be important in the pathogenesis of inflammatory bowel disease.
authors.affiliation: University Department of Medicine, Royal Free Hospital School of Medicine, London, England.
authors.forename: N P
authors.initials: NP
authors.lastname: Thompson
authors.forename: A J
authors.initials: AJ
authors.lastname: Wakefield
authors.forename: R E
authors.initials: RE
authors.lastname: Pounder
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001778:Blood Coagulation Disorders / Q000150:complications* / Q000453:epidemiology / Q000235:genetics; D016009:Chi-Square Distribution; D002648:Child; D002675:Child, Preschool; D003093:Colitis, Ulcerative / Q000150:complications* / Q000453:epidemiology; D003424:Crohn Disease / Q000150:complications* / Q000453:epidemiology; D005260:Female; D006467:Hemophilia A / Q000150:complications; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011795:Surveys and Questionnaires; D006113:United Kingdom / Q000453:epidemiology; D014842:von Willebrand Diseases / Q000150:complications