Inflammatory bowel diseases, Crohn’s disease (CD) and ulcerative colitis (UC), are chronic conditions in which idiopathic inflammation of the gastrointestinal tract wall is the characteristic feature.
The etiology of these disorders is not fully elucidated, proposed causes including environmental, immunological and genetic factors. A consensus hypothesis is that in genetically susceptible individuals, both exogenous factors (eg. Intestinal flora) and factors related to the host (barrier function of epithelial cells, innate and acquired immune response function) produce a chronic immune dysfunction in the intestinal mucosa which is further modified by the action of environmental factors (eg. smoking).