Crohn's disease

Crohn's Disease is a chronic granulomatous disease that typically affects the terminal ileum and well demarcated areas of large bowel with relatively normal bowel disease. The disease is named for its discoverer, Dr. Burrill B. Crohn[?]. It can affect any part of the alimentary tract from the mouth to the anus. It is often associated with auto-immune disorders outside the bowel, such as mouth ulcers and rheumatoid arthritis. Given the high incidence of irritable bowel syndrome among Americans, this can also be a complicating factor.

Crohn's patients typically suffer from chronic diarrhea and disrupted digestion, making it difficult for sufferers in the acute phase of the disease to eat and/or digest food. The inflammation can be extremely painful and debilitating. Other common complications of Crohn's include fistulas of the colon, hemorrhoids, lipid, absorption problems, and anemia.

The disease typically first appears in a sufferer by age 30 or so, though it is not unknown for symptoms to first appear quite late in life. It quite commonly appears in childhood. Some estimates suggest that up to 1,000,000 Americans have the disease, suggesting that the prevalence of it is around 1 in 300. Some ethnic groups have significantly higher rates of prevalence than others. Increased rates of disease have also been noted in some families, leading to speculation of a possible genetic link, especially in the HLA-B27[?] MHC allele. Research indicates that Crohn's is a disease of civilization[?], in other words, the incidence of the disease is much higher in industrialized countries than elsewhere.

The disease has long been suspected of being due to a Mycobacteria[?] because of the similarity of many features to human tuberculosis and veterinary Ovine Jonnes Disease[?], but to date no specific organism has been detected. It is probably a combination of an infection from one or several organisms together with an altered immune response. A class of organisms know as "cell wall-deficient bacteria," which can prime autoimmune reactions, is a current topic of research.

The bowel shows segmental "hose pipe" thickening and shows full thickness chronic inflammation, giant cell granulomas[?], and fissures[?] with acute inflammation. Bowel obstruction[?] is common. This may require surgical resection. Approximately 50% of surgical cases require additional surgery within five years because the disease tends to reappear at the site where the bowel was rejoined, and some patients eventually develop short bowel syndrome[?] which makes it extremely difficult to digest food. For this reason, surgery is considered by many doctors only as a last resort in the treatment of Crohn's.

Since no cure for Crohn's has been found, treatment for Crohn's disease is largely a question of managing the symptoms. Some patients find some foods (examples including foods high in fiber, and dairy foods) make their symptoms worse, but the disease cannot be controlled simply through diet modifications. Therapies include treatment with anti-inflammatory drugs that act in the intestines, and, if symptoms cannot be controlled with other drugs, with steroids (although long-term steroid therapy is discouraged because of its well-known side effects). There are newer drugs used in the treatment of Crohn's, including the 5-ASA drugs such as Pentasa and Asacol and immuno-suppressing drugs like Remicade[?]. Research trials are being conducted on treatment with drugs in the same family as thalidomide.

Some patients can be treated with the existing drugs quite effectively and can go into long-term remission[?], sufficient to allow the sufferer to lead a normal life. Patients are at somewhat larger risk of colon cancers, and consequently undergo regular colonoscopies[?] both to check for precancerous growths and to monitor the success of treatment. It does not seem to have as great a risk of malignancy compared to Ulcerative colitis. The classic cases of Crohn's and Ulcerative colitis are distinct disease but in practice there are often "overlap" cases of chronic inflammatory bowel disease.

Crohn's disease is often misdiagnosed as food poisoning, gastroenteritis[?], appendicitis (due to the common locus of pain in the lower right-hand quadrant of the abdomen), and irritable bowel syndrome.

External links

• Genetics of Crohn's Disease (http://my.webmd.com/content/article/2/3204_672.htm)
• Crohn's Disease - WebMed (http://my.webmd.com/content/article/5/1680_50985.htm)
• Crohn's Disease - HealthAtoZ (http://www.healthatoz.com/healthatoz/Atoz/ency/crohns_disease)

See also: Gastroenterology