Pathogenesis of Post-operative Crohn's Disease Recurrence

The recurrence of Crohn's disease following ileocecal resection is a common and serious problem. The aim of this thesis is to characterize changes in the neo-terminal ileum after ileocolonic anastomosis using IL-10 gene deficient mice prone to develop Crohn's disease. Ileocolonic anastomosis resulted in altered bacterial profile in the neo-terminal ileum and an increase in mucosal expression of TNF and TGF-beta mRNA as well as systemic IFN-gamma and IL-17 in response to endogenous bacterial antigens. Elevated mucosal TGF-beta mRNA coincided with increased collagen deposition in the bowel wall of the neo-terminal ileum. On histology there was no mucosal inflammation, however, significant infiltration of mesenteric fat with lymphocytes and neutrophils was noted. Net glucose transport in the small bowel was not affected by ileocolonic anastomosis. This project demonstrated that a number of changes occur following ileocolonic anastomosis that may play a role in post-operative disease recurrence.