Age-dependent phenotypic clinical expression of Crohn's disease.

Crohn's disease is a heterogeneous disorder that involves different sites along the length of the gastrointestinal tract. It is usually characterized by a high rate of strictures and penetrating complications. The present study used the modified Vienna classification schema to explore the specific role of age at diagnosis on both disease location and disease behavior. There were 1,015 consecutively evaluated patients, including 449 males and 566 females. Disease was most often localized in the ileocolon and could be most often classified as complex disease (ie, in >70%) with strictures or penetrating complications. For both males and females, with increasing age at diagnosis, disease became less extensive, more often localized in the colon alone, and disease behavior could be characterized as more complex, especially with penetrating disease complications. These results demonstrate the phenomenon of age dependence in the phenotypic clinical expression of Crohn's disease.