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Crohn's disease is a form of inflammatory bowel disease (IBD). The body's immune system attacks the gastrointestinal tract, causing chronic inflammation. Normally, the immune system helps protect the body, but with Crohn's disease the immune system can't tell the difference between good substances and foreign invaders; in particular, it may be overreacting to normal bacteria in the intestines. The result is an overactive immune response that leads to chronic inflammation -- a condition also known as an autoimmune disorder.
The human immune system is made from cells and different proteins that protect people from infection. One explanation of Crohn's disease is that the body’s immune system mistakenly identifies as foreign substances the harmless and even beneficial bacteria, foods, and other substances that pass through the intestine. The immune system’s response is to attack these “invaders.” During this process, white blood cells accumulate in the lining of the intestines, producing chronic inflammation, which leads to ulcerations and bowel injury.
Scientists do not know if the abnormality in the functioning of the immune system in people with Crohn’s disease is a cause, or a result, of the disease. Research suggests that several factors may cause the gastrointestinal tract to become inflamed, including genetic inheritance, the actual immune system, and the foreign substances, or antigens, in the environment outside the body. These antigens themselves might cause the inflammation, or the body's reaction to them might cause the immune system to become over-reactive and thus lead to inflammation. Scientists have found that people with Crohn’s disease have high levels of tumor necrosis factor (TNF), a protein produced by the immune system, circulating inside their bodies.
Crohn's-related inflammation usually affects the intestines, but may occur anywhere from the mouth to the end of the rectum (anus). Also known as granulomatous colitis and regional enteritis, Crohn’s causes a wide variety of symptoms. In response to inflammation, the intestine swells and the intestinal wall thickens, resulting in chronic pain and diarrhea. Other signs of Crohn's Disease include abdominal pain, diarrhea (which may be bloody), vomiting, or weight loss, cause complications outside of the gastrointestinal tract such as skin rashes, arthritis and inflammation of the eye.
There is evidence of a genetic link to Crohn's disease. Individuals with siblings afflicted with the disease are themselves at higher risk. About 20 percent of people with Crohn’s disease have a blood relative with some form of inflammatory bowel disease, most often a brother or sister and sometimes a parent or child. People of Jewish heritage have an increased risk of developing Crohn’s disease, and African Americans are at decreased risk for developing Crohn’s disease.
However, Crohn's may also have a large environmental component, because there are a higher number of cases in western industrialized nations than in poor countries. For example, Crohn’s disease affects between 400,000 and 600,000 people in North America, and in Northern Europe the disease affects 27–48 people per 100,000. Males and females are equally affected, but smokers are three times more likely to develop Crohn's disease. Although the disease can occur at any age, the monster tends to strike first in the teens and twenties, and may also attack people in their fifties to seventies.
Crohn's Disease is incurable either with medicine or surgery. Treatment can only help you control symptoms, get the disease into remission and prevent relapse.
The disease was named for American gastroenterologist Burrill Bernard Crohn, who in 1932, along with two colleagues, described a series of patients with inflammation of the terminal ileum, the area most commonly affected by the illness. For this reason, the disease has also been called regional ileitis or regional enteritis. The condition, however, has been independently identified by others in the literature prior, most notably in 1904 by Polish surgeon Antoni Lesniowski for whom the condition is additionally named (Lesniowski-Crohn's disease) in the Polish literature.
Crohn's is hard to diagnose because its symptoms are similar to those of other intestinal disorders, such as irritable bowel syndrome and ulcerative colitis. However, there are differences. While ulcerative colitis causes inflammation and ulcers in the top layer of the lining of the large intestine, in the case of Crohn’s disease, all layers of the intestine may be involved, and normal healthy bowel can be found between sections of diseased bowel.
Diagnostic research has identified five different types of Crohn's disease: - Ileocolitis, or Ileocolic Crohn's disease, is the most common form, and accounts for fifty percent of cases. It consists of the inflammation of the ileum -- the lowest part of the small intestine == and the colon, also known as the large intestine.
- Ileitis is the inflammation of the ileum alone, and accounts for thirty percent of cases.
- Crohn's colitis only affects the large intestine. It accounts for the remaining twenty percent of cases and may be particularly difficult to distinguish from ulcerative colitis, another type of disease entirely, which causes similar symptoms.
As any of these three basic types of Crohn's disease progresses through the body, they may evolve into (4) gastroduodenal Crohn's disease, which causes inflammation in the stomach and first part of the small intestine, called the duodenum, or (5) Jejunoileitis, which causes spotty patches of inflammation in the top half of the small intestine (jejunum). *This article is based on the information at AARP Health Tools, Wikipedia and National Institutes of Health |
