Incidence of inflammatory bowel disease in Corsica from 2002 to 2003

The aim of this prospective epidemiological study was to determine the incidence of inflammatory bowel diseases (IBD) in Corsica using the same methodology as that of the EPIMAD registry.

Between January 1st, 2002 and December 31, 2003, all gastroenterologists in Corsica (N=19) enrolled patients consulting for the first time with clinical symptoms compatible with IBD. Each case was reviewed by another expert gastroenterologist to assign a diagnosis of definite, probable, possible Crohn's disease (CD), ulcerative colitis (UC) or unclassified/able chronic colitis.

Eighty-one new cases were recorded, including seventy-one diagnoses of IBD (definite and probable cases), with 20 (28%) CD, 49 (69%) UC and 2 (3%) unclassifiable chronic colitis. The age-adjusted incidence (per 105 inhabitants/year) was 4.05 for CD and 9.5 for UC. The female/male ratio and median age at time of diagnosis were 1.3 and 29 years for CD and 0.63 and 44 years for UC, respectively. The median time from symptom onset to diagnosis was five months for both diseases.

In Corsica, the observed incidence of CD is close to that observed in other metropolitan French regions. These data are contrary to the north-south gradient reported for this disease. Our figure of 9.5/10(5) for UC in Corsica is two-fold higher than reported in other metropolitan French regions. Genetic and/or environmental factors may explain these findings.