[Recent data on the epidemiology and etiology of Crohn's disease]

The disease described by Crohn and co-workers fifty years ago escapes precise definition as it involves not only the ileum but the whole digestive tract. When restricted to the colon, it cannot easily be differentiated from that other inflammatory disease of the large bowel: ulcerative colitis. Meanwhile, Crohn's disease seems to be increasingly frequent, spreading from north to south, with a higher incidence among Jews and relatives of patients presenting with the condition. This would suggest interaction between a specific genetic factor and an as yet undetermined environmental agent which becomes pathogenic in the digestive tract. The lesions of Crohn's disease point to an immune conflict but so far, no definite disorder of the immunoregulation system has been demonstrated.