Although there are many theories about what causes Crohn's disease, none of them have been proven. So exactly what causes it is unknown. There is a benefit, though, in understanding the possible causes of Crohn's disease and how they interact with one another. Doing so can help one better understand the symptoms, diagnosis, and treatment of Crohn's disease.
Scientists believe that Crohn's disease is caused by a combination of these factors:
Immune system problems