The Causes of Crohn's Disease. We don’t know the cause of Crohn’s disease. We theorize that Crohn’s disease happens as a result of three types of derangements. The first is that the body’s immune system is over-reactive. The second is that the body keeps a barrier between the outside of the body and the inside of the body within the intestine, and we think that barrier between the outside environment such as the stool versus the inside environment such as the vessels and the intestine are somewhat broken down, and it is much easier for any substance or anything that can irritate the immune system or activate the immune system, has easier access to the immune system. And then the third process that we think happens is there probably is a change in the intestinal environment or what is within the intestine in patients with inflammatory bowel disease, and this could be bacteria or other organisms as well as dietary particles that act as the triggers or antigen for the immune response.
