Inflammatory bowel disease, or IBD, causes chronic inflammation of the intestinal tract. The inflammation can also involve organs other than the intestines. Ulcerative colitis and Crohn's disease are the two most common inflammatory bowel diseases. The exact cause of IBD remains unknown, but environmental factors, improper immune responses and genetics may play a role in the development of the disorder.
Improper Immune Response
The immune system recognizes foreign cells, tissues, objects and organisms inside the body. The immune system initiates an immune response to fight off the foreign invaders. After the immune system fights off the foreign invader, it turns itself off. In IBD, an initial trigger, such as an infection from a bacteria or virus or something taken in from the diet or the surrounding environment, activates an immune response. However, the immune system in those who develop IBD does not turn off after the elimination of the initial trigger. The immune system constantly attacks the protective immune cells that line the intestines. The immune cells develop chronic inflammation in response to the constant attack. The chronic inflammation leads to a variety of symptoms that include diarrhea, rectal bleeding, urgency to have bowel movements, abdominal cramps and pain, and fever and weight loss.
Environmental Factors
The American College of Gastroenterology considers cigarette smoking and a prior history of smoking as the most significant environmental factor causing IBD. The Centers for Disease Control reports that certain types of diets and variations in exposure to sunlight, pollution and industrial chemicals contribute to the development of IBD as well.
Genetic Predisposition
The American College of Gastroenterology points out that 10 to 20 percent of people with IBD have one or more other family members affected with IBD. According to the CDC, people who have a sibling, parent or child with IBD have a greater risk of developing the disorder than those who don't. IBD occurs more in people born of Caucasian and Ashkenazic Jewish origin than in other racial and ethnic subgroups.
