Crohn’s disease is an inflammatory bowel disease (IBD) in which areas of the intestinal tract become inflamed causing sloughing and, in some instances, ulcers. While many other IBDs cause inflammation of the intestinal lining, Crohn’s affects all layers of the intestine, not just the surface.
Although usually affecting the portion of the small intestine known as the ileum the condition is not limited solely to the small intestine and can affect any area of the digestive tract, from the mouth to the anus. Severity varies: Only a small area of intestine is affected in some people, while others suffer from widespread intestinal inflammation. A Crohn’s disease diagnosis is most often made between the ages of 15 and 35, but people can develop Crohn’s at any age.
What Causes Crohn’s Disease?
The causes of Crohn’s disease remain a mystery, but many researchers believe that the disease is triggered by a faulty immune system. Either the immune system responds too aggressively to bacteria in the intestine, or it may even perceive normal food and intestinal contents as a threat. This results in inflammation and the sudden emptying of the intestines.
Heredity may play a role in the development of Crohn’s disease. While it is a relatively rare disease, approximately 20 to 25 percent of people with Crohn’s have a close relative, generally a sibling or parent, who also has Crohn’s or ulcerative colitis. It is also disproportionately common among ethnic groups, such as Eastern European Jews, further implicating heredity and genetics as causes of Crohn’s disease. In fact, people of Jewish heritage are three to four times as likely to develop Crohn’s disease as people from other ethnic groups.
A British research team at St. George’s Hospital Medical School in London has discovered that 92 percent of Crohn’s disease patients harbor the bacterium Mycobacterium avium paratuberculosis (MAP) in their intestinal tissues. Only 26 percent of patients without Crohn’s disease have MAP. This implicates the bacterium as a cause of Crohn’s disease inflammation. MAP (the same bacterium that causes Johne’s disease in cattle) is a contaminant of unpasteurized milk and dairy products.
Crohn’s Diagnosis: The Colonoscopy
Arriving at a diagnosis can be difficult, as so many of its symptoms, especially stomach pain, mimic other bowel diseases such as irritable bowel syndrome or ulcerative colitis. Stomach pain is a very common complaint and, unfortunately, this symptom may point to a variety of causes, making diagnosis a challenge. In order to firmly establish an accurate diagnosis, a colonoscopy may be preformed. A colonoscopy is a specialized form of endoscopy, a procedure in which a thin fiber optic tube with a tiny camera attached is inserted into the body to examine the digestive tract.
When endoscopy is used to diagnose Crohn’s disease, the endoscope is inserted through the rectum to examine the colon for areas of inflammation.
One of the benefits of endoscopy is that, if needed, the endoscope can also be used to obtain tissue samples for biopsy.
American Society of Colon and Rectal Surgeons. (nd). Crohn’s disease.
Carson-Dewitt, R.S. (2002, December). Crohn’s disease. Gale Encyclopedia of Medicine.