theories about what causes crohn's disease abound but none has been proven. the most popular theory is that the body's immune system reacts to a virus or a bacterium by causing ongoing inflammation in the intestine. people with crohn's disease tend to have abnormalities of the immune system but doctors do not know whether these abnormalities are a cause or result of the disease. crohn's disease is not caused by emotional distress.
what causes crohn's disease?