title: [Epidemiological developments and insights in chronic inflammatory bowel diseases].
abstract: In the Western world, a sharp increase in the incidence of both Crohn's disease and ulcerative colitis was observed during the sixties and seventies, after which it reached a plateau at around 7 and 12 new cases per 100,000 inhabitants per year, respectively. Both chronic inflammatory bowel diseases usually commence between 15 and 30 years of age. Most patients have a normal life expectancy. A multifactorial model has been proposed to explain the pathogenesis, in which there seems to be an interaction between genetic predisposition, environmental factors and an altered immune response (occurring either after or because of the disease). Smoking is a clear risk factor in the development of Crohn's disease and it also negatively influences the clinical outcome. On the other hand, stopping smoking is a risk factor in the development of ulcerative colitis.
authors.affiliation: Academisch Ziekenhuis, afd. Gastro-enterologie, Postbus 5800, 6202 AZ Maastricht. mru@sint.azm.nl
authors.forename: M G
authors.initials: MG
authors.lastname: Russel
authors.forename: R W
authors.initials: RW
authors.lastname: Stockbrügger
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D003093:Colitis, Ulcerative / Q000453:epidemiology / Q000209:etiology; D003424:Crohn Disease / Q000453:epidemiology / Q000209:etiology; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D007111:Immunity, Cellular; D015994:Incidence; D015212:Inflammatory Bowel Diseases / Q000453:epidemiology* / Q000209:etiology* / Q000235:genetics / Q000276:immunology; D008019:Life Style; D008297:Male; D008954:Models, Biological; D009426:Netherlands / Q000453:epidemiology; D015995:Prevalence; D012307:Risk Factors; D017678:Sex Distribution; D012907:Smoking / Q000453:epidemiology; D015996:Survival Rate