# Structural Biochemistry/Crohn's Disease
### Crohn's Disease

Another disease that involves the digestive system, Crohn’s disease, causes inflammation within the digestive tract. The end part of the small intestine called the ileum is the most commonly affected towards the Crohn’s disease. Normally, the movement of muscles in the GI tract and the release of hormones and enzymes allows for the digestion of food. However, in Crohn’s disease, inflammation occurs in the inner lining of the affected part of the GI tract and the subsequent effect of inflammation and swelling can cause pain and can cause emptiness within the intestines, resulting in diarrhea. A long lasting type of inflammation may produce scar tissue that builds up inside the intestine to create a stricture, a narrowed passageway that can decrease the movement of food through the intestine, causing pain or cramps. Crohn’s disease is considered an inflammatory bowel disease, the general name for diseases that cause inflammation and irritation in the intestines. Crohn’s disease can be difficult to diagnose because its symptoms are similar to other intestinal disorders, such as ulcerative colitis. For example, ulcerative colitis and Crohn’s disease both share the characteristics of abdominal pain and diarrhea.
Crohn's disease is a chronic inflammatory process primarily involving the intestinal tract. Although it may involve any part of the digestive tract from the mouth to the anus, it most commonly affects the last part of the small intestine (ileum) and/or the large intestine (colon and rectum). Crohn's disease is a chronic condition and may recur at various times over a lifetime. Some people have long periods of remission, sometimes for years, when they are free of symptoms. There is no way to predict when a remission may occur or when symptoms will return.

## Symptoms

Because Crohn's disease can affect any part of the intestine, symptoms may vary greatly from patient to patient. Common symptoms include cramping, abdominal pain, diarrhea, fever, weight loss, and bloating. Not all patients experience all of these symptoms, and some may experience none of them. Other symptoms may include anal pain or drainage, skin lesions, rectal abscess, fissure, and joint pain (arthritis).
Common Crohn's symptoms: •Cramping - abdominal pain •Diarrhea •Fever •Weight loss •Bloating •Anal pain or drainage •Skin lesions •Rectal abscess •Fissure •Joint pain
Who does Crohn's disease affect? Any age group may be affected, but the majority of patients are young adults between 16 and 40 years old. Crohn's disease occurs most commonly in people living in northern climates. It affects men and women equally and appears to be common in some families. About 20 percent of people with Crohn's disease have a relative, most often a brother or sister, and sometimes a parent or child, with some form of inflammatory bowel disease. Crohn's disease and a similar condition called ulcerative colitis are often grouped together as inflammatory bowel disease. The two diseases afflict an estimated two million individuals in the U.S.

## Causes

The exact cause is not known. However, current theories center on an immunologic (the body's defense system) and/or bacterial cause. Crohn's disease is not contagious, but it does have a slight genetic (inherited) tendency. An x-ray study of the small intestine may be used to diagnose Crohn's disease.

## Treatment

Initial treatment is almost always with medication. There is no "cure" for Crohn's disease, but medical therapy with one or more drugs provides a means to treat early Crohn's disease and relieve its symptoms. The most common drugs prescribed are corticosteroids, such as prednisone and methylprednisolone, and various anti-inflammatory agents. Other drugs occasionally used include 6-mercaptopurine and azathioprine, which are immunosuppressive. Metronidazole, an antibiotic with immune system effects, is frequently helpful in patients with anal disease. In more advanced or complicated cases of Crohn's disease, surgery may be recommended. Emergency surgery is sometimes necessary when complications, such as a perforation of the intestine, obstruction (blockage) of the bowel, or significant bleeding occur with Crohn's disease. Other less urgent indications for surgery may include abscess formation, fistulas (abnormal communications from the intestine), severe anal disease or persistence of the disease despite appropriate drug treatment.
While it is true that medical treatment is preferred as the initial form of therapy, it is important to realize that surgery is eventually required in up to three-fourths of all patients with Crohn's. Many patients have suffered unnecessarily due to a mistaken belief that surgery for Crohn's disease is dangerous or that it inevitably leads to complications. Surgery is not "curative," although many patients never require additional operations. A conservative approach is frequently taken, with a limited resection of intestine (removal of the diseased portion of the bowel) being the most common procedure. Surgery often provides effective long-term relief of symptoms and frequently limits or eliminates the need for ongoing use of prescribed medications. Surgical therapy is best conducted by a physician skilled and experienced in the management of Crohn's disease.
What is a colon and rectal surgeon? Colon and rectal surgeons are experts in the surgical and non-surgical treatment of diseases of the colon, rectum and anus. They have completed advanced surgical training in the treatment of these diseases as well as full general surgical training. Board-certified colon and rectal surgeons complete residencies in general surgery and colon and rectal surgery, and pass intensive examinations conducted by the American Board of Surgery and the American Board of Colon and Rectal Surgery. They are well-versed in the treatment of both benign and malignant diseases of the colon, rectum and anus and are able to perform routine screening examinations and surgically treat conditions if indicated to do so.

## Genetic study

Scientists have recently conducted new research into the genetics of inflammaroy bowel disease such as Crohn's disease and ulcerative colitis. These research studies have recently reveals new insights into the origin of this set of illnesses.
Researchers have presented information of linked genetic variations in 163 regions of the human genome that are at heightened risk of developing inflammatory bowel disease (IBD). Of those discovered regions, 71 are newly discovered. IBD includes various automimmune digestive disorders that affect nearly 2.5 million people worldwide. Symptoms include abdominal pain and diarrhea. Patients with IBD typically have to undergo lifelong treatment with medications and other forms of drug therapy.
In recent studies, researchers analyzed data from about 34,000 people who took part in 15 previous studies of either Crohn's disease or ulcerative colitis. They also examined more than 41,000 DNA samples data from genome-wide scans of patients of Crohn's disease and ulcerative colitis. These samples were collected around the world from 11 different centers.
Since 163 regions were found to develop IBD, 71 were newly found and the other 92 regions were confirmed. Both groups were confirmed to be prone to inflammatory bowel disease. The way these regions were analyzed was done by overlapping those linked with other autoimmune diseases, suggesting IBD results from overactive immune defense systems that can evolve into serious bacterial infections.
Sceintists have stated, "Until this point we have been studying the two main forms of IBD -- Crohn's disease and ulcerative colitis -- separately," co-lead author Judy Cho, professor of gastroenterology and genetics at Yale School of Medicine, said in a Yale news release. "We created this study based on what seems to be a vast amount of genetic overlap between the two disorders." The new studies reveal "a genetic balancing act between [the immune system] defending against bacterial infection and attacking the body's own cells," co-lead author Jeffrey Barrett of the Wellcome Trust Sanger Institute in Cambridge, England, said in the news release. "Many of the regions we found are involved in sending out signals and responses to defend against bad bacteria. If these responses are over-activated, we found it can contribute to the inflammation that leads to IBD."

### References

* ↑ , Crohn's Disease.
Preidt, Robert. Yale University, news release, Oct. 31, 2012. <http://www.nlm.nih.gov/medlineplus/news/fullstory_130861>