Incidence of Inflammatory Bowel Disease in the Province of Liege (Belgium). La Societe De Gastroenterologie Liegeoise

Up to now, as there is no national registry of patients with inflammatory bowel disease (IBD) in Belgium, the study of IBD epidemiology in our country is only possible through institutional or regional series. Therefore we conducted a prospective epidemiologic study of IBD in the Province of Liege (1 million inhabitants). Methods : 29 (out of 47) private and public gastroenterologists completed a standard questionnaire for each patient consulting for the first time with clinical symptoms compatible with IBD between 1/06/1993 and 31/05/1994. Results : During that period 104 cases of IBD were recorded : 56 (54%) Crohn's disease (CD), 36 (35%) ulcerative colitis (UC) including 7 proctitis (19% of UC) and 12 (11%) unclassified colitis. The annual incidence was 5.5 per 100.000 for CD and 3.5 for UC. The sex ratio F/M was 1.7 for CD and 0.7 for UC. The median age at the time of diagnosis was 33.5 yrs for CD and 40 yrs for UC. The highest age specific incidence rate for CD and UC was between 20 and 29 yrs : 13.6 and 6.1, respectively. Conclusions : This first Belgian prospective study has shown an incidence rate for CD comparable with that seen in north European studies but lower than that seen for UC. These results were similar to those observed in the northen part of France. Belgium appears to be a privileged country to undertake a national register and to study epidemiological aspects of IBD.