The aim of the study was to examine the influence of age at diagnosis of Crohn's 
disease on disease site and course in Tunisian patients.
METHODS: All hospital patients for Crohn's disease between 1993 and 2002 were 
included. They were segregated by age at diagnosis as follows: younger than 20 
years, 20-39 years, and 40 years or older. And all patients were classified at 
the time of the latest visit into one of three subtypes of disease (non 
complicating, stricturing, and fistulizing) according Vienna's classification. 
Crohn's disease was devised also by site (ileum, ileocecal, colon and higher 
site).
RESULTS: Sixty one patients (50.4%) were 20-39 years old and 43 patients (35.5%) 
were 40 years and older. Colonic involvement was significantly more common 
(46,5%) in the 40 years and older group compared with 20-39 years group (24.6%) 
(p = 0.01). The subtype without complication was significantly more common 
(58.1%) in the 40 years and older group compared with 20-39 years group (39.3%) 
(p = 0.05). The frequency of the need for surgery for any indication for Crohn's 
disease didn't differ significantly according to age.
CONCLUSION: In this study, Crohn's disease diagnosed in tunisian patients that 
were 40 years and older had often a colonic site and a less severe phenotype 
supporting the concept of genetic heterogeneity.