 While the causes of Crohn's disease are unknown, it is believed to be due to a combination of environmental, immune, and bacterial factors in genetically susceptible individuals.It results in a chronic inflammatory disorder, in which the body's immune system attacks the gastrointestinal tract, possibly targeting microbial antigens.While Crohn's is an immune-related disease, it does not appear to be an autoimmune disease (in that the immune system is not being triggered by the body itself).