Crohn's disease, is an inflammatory bowel disease that may affect any part of the gastrointestinal tract from mouth to anus, causing a wide variety of symptoms. It can be categorized either by the specific tract region affected or by the behavior of disease as it progresses.
Crohn’s disease should be differentiated from Irritable bowel syndrome (IBS), or spastic colon. IBS is a functional bowel disorder characterized by chronic abdominal pain, discomfort, bloating, and alteration of bowel habits in the absence of any detectable organic cause. IBS is often regarded as a syndrome or collection of symptoms rather than a disease.
Crohn’s disease and ulcerative colitis (UC) are chronic inflammatory conditions of the intestinal tract. The two diseases are often grouped together as inflammatory bowel disease (IBD) because of their similar symptoms. They are, however, very different conditions where the main difference is the location and nature of the inflammatory changes.
It primarily causes abdominal pain, diarrhea, vomiting or weight loss, but may also cause complications outside the gastrointestinal tract such as skin rashes, arthritis, and inflammation of the eye. Crohn's disease, like many other chronic, inflammatory diseases, can cause a variety of systemic symptoms. Among children, growth failure is common.
The prevalence for Northern Europe has ranged from 27–48 per 100,000. Crohn's disease is more common in northern countries, and shows a higher preponderance in northern areas of the same country. Crohn's disease tends to present in two peaks, initially in the teens and twenties, with another peak incidence in the fifties to seventies, although the disease can occur at any age.
There is evidence of a genetic link to Crohn's disease, putting individuals with siblings afflicted with the disease at higher risk. In contrast to many other autoimmune diseases males and females are equally affected.
Many people with Crohn's disease have symptoms for years prior to the diagnosis. The diagnosis of Crohn's disease can sometimes be challenging, and a number of tests are often required to assist the physician in making the diagnosis. The diagnostic tools include endoscopy/biopsy, radiology, nuclear scan and serology. It is important to be able to make a differential diagnosis between Crohn’s and ulcerative colitis as the two diseases have different prognosis and treatment strategies.