Crohn's disease causes chronic inflammation of the gastrointestinal tract. It is one form of a condition known as inflammatory bowel disease.

What is going on in the body?

The cause of Crohn's disease is unknown. It is thought to be an autoimmune disorder. This means that the body's immune system attacks itself. The immune attack results in chronic inflammation of the gastrointestinal tract and other parts of the body.

What are the causes and risks of the disease?

The cause of Crohn's disease is not known, but it is thought to be an autoimmune disorder. Inherited factors also may play a role, since 20% to 25% of the people who have Crohn's disease have a close relative with this disease or a similar disease. Crohn's disease is more common among whites than blacks. Men and women are affected equally. The disease usually starts between 15 and 35 years of age.

New research findings suggest that autoimmune disorders may be triggered by a transfer of cells between the fetus and the mother during pregnancy. The study involved women with scleroderma, an autoimmune disorder involving the skin. These women have more fetal cells in their blood decades after a pregnancy than women who don't have scleroderma. While further research is needed to substantiate these findings, the study does offer an explanation for the much higher incidence of autoimmune disorders in women than in men.