Crohn’s disease is one of the myriad ailments for which no definite cause is known. The Mayo Clinic explains, “Researchers believe that a number of factors, such as heredity and a malfunctioning immune system, play a role in the development of Crohn’s disease.” In fact, genetic testing can even narrow down gastrointestinal issues to a small number of recognized diseases. The causes of Crohn’s disease may be one, some or all of these factors. The very nature of the disease, however, makes it very difficult to determine what might have caused the disease, and what might have been caused by the disease by the time a diagnosis is made.
Immune response. One of the most definite causes of the inflammation characteristic of Crohn’s disease is an abnormal immune response within the body. This response sends white blood cells to certain areas of the digestive tract where there is no infection, and subsequently causes moderate to severe inflammation in that area.
Genetic factors. The understanding of Crohn’s disease has advanced to the point that medical researchers can pinpoint contributing genes in a genetic test. However, in many cases, these tests are not used for diagnosis unless there is doubt regarding the nature of the disease or if more standard tests cannot be performed for any reason. Crohn’s disease and related disorders are known to run in families and ethnic groups.
The environmental link. While the exact role of the environment hasn’t been definitively identified, it is known that people who live in certain areas or conditions are more likely to have Crohn’s disease. Specifically, if you’re in an urban area, especially a northern one, you are probably at higher risk for having Crohn’s disease. Researchers believe that the genetic factor must already be there, but something in the home environment — speculation runs toward pollution and/or diet factors — correlates with higher Crohn’s risk. This has been studied in populations that have moved from low-risk environments to high-risk environments, and the results have shown that the risk will rise even in families that previously had no issues with Crohn’s and related diseases.