Crohn's Disease in Children and Teens Causes

Diet and stress do not cause Crohn's disease. They can worsen the symptoms, but they are not the cause of the disease.

We do not know exactly what causes Crohn's disease. Apparently an unknown triggering event alters the immune response in a genetically susceptible person. This abnormal immune response leads to ongoing inflammation of the intestines. Various immune abnormalities are common in individuals with Crohn's disease.

We do not know what makes a person "genetically susceptible" to Crohn's disease. In about 15%-20% of people, the disease runs in the family. This is especially true of people who develop the disease at a younger age. Several genes have been linked to the disease, but there is no clear pattern to how these genes interact to cause the disease. Mutations in one gene, called CARD15, are present in about 40% of people with Crohn's disease. However, this gene is also frequently present in healthy people who never develop this disease.

We also do not know what the triggering event might be. The bacteria that naturally live in the intestines (or some other bacteria or virus) may play a role in triggering the onset of the disease.