Crohns Disease

Crohn's disease, a type of inflammatory bowel disease (IBD), is a condition in which the lining of your digestive tract becomes inflamed, causing severe diarrhea and abdominal pain. The inflammation often spreads deep into the layers of affected tissue. Like ulcerative colitis, another common IBD, Crohn's disease can be both painful and debilitating and sometimes may lead to life-threatening complication.

While there's no known medical cure for Crohn's disease, therapies can greatly reduce the signs and symptoms of Crohn's disease and even bring about a long-term remission. With these therapies, many people afflicted with Crohn's disease are able to function normally in their everyday lives.

Causes:
The exact cause of Crohn's disease is unknown. However, genetic and environmental factors have been invoked in the pathogenesis of the disease. Research has indicated that Crohn's disease has a strong genetic link. The disease runs in families and those with a sibling with the disease are 30 times more likely to develop it than the normal population. Ethnic background is also a risk factor. Until very recently, whites and European Jews accounted for the vast majority of the cases in the United States, and in most industrialized countries, this demographic is still true.

Mutations in the CARD15 gene (also known as the NOD2 gene) are associated with Crohn's disease and with susceptibility to certain phenotypes of disease location and activity. In earlier studies, only two genes were linked to Crohn's, but scientists now believe there are over eight genes that show genetics play a crucial role in the disease.

It's possible that a virus or bacterium may cause Crohn's disease. When your immune system tries to fight off the invading microorganism, the digestive tract becomes inflamed. One microorganism that may be involved in the development of Crohn's is Mycobacterium avium subspecies paratuberculosis (MAP), a bacterium that causes intestinal disease in cattle. Researchers have found MAP in the blood and intestinal tissue of many people with Crohn's disease, but only rarely in people with ulcerative colitis.

There's no clear evidence that MAP causes Crohn's disease. Some researchers believe that a genetic susceptibility may trigger an abnormal response to the bacterium in some people. Currently, most investigators believe that some people with the disease develop it because of an abnormal immune response to bacteria that normally live in the intestine.

Symptoms:
Signs and symptoms of Crohn's disease can range from mild to severe and may develop gradually or come on suddenly, without warning. They include:

Diarrhea- The inflammation that occurs in Crohn's disease causes cells in the affected areas of your intestine to secrete large amounts of water and salt. Because the colon can't completely absorb this excess fluid, you develop diarrhea. Intensified intestinal cramping also can contribute to loose stools. In mild cases, stools may simply be looser or more frequent than usual. But people with severe disease may have dozens of bowel movements a day, affecting both sleep and ordinary activities.
Abdominal pain and cramping- Inflammation and ulceration may cause the walls of portions of your bowel to swell and eventually thicken with scar tissue. This affects the normal movement of intestinal tract contents through your digestive tract and may lead to pain and cramping. Mild Crohn's disease usually causes slight to moderate intestinal discomfort, but in more serious cases, the pain may be severe and occur with nausea and vomiting.
Blood in your stool- Food moving through your digestive tract can cause inflamed tissue to bleed, or your bowel may also bleed on its own. You might notice bright red blood in the toilet bowl or darker blood mixed with your stool. You can also have bleeding you don't see (occult blood). In severe disease, bleeding is often serious and ongoing.
Ulcers- Crohn's disease begins as small, scattered sores on the surface of the intestine. Eventually these sores may become large ulcers that penetrate deep into — and sometimes through — the intestinal walls. You may also have ulcers in your mouth similar to canker sores.
Reduced appetite and weight loss- Abdominal pain and cramping and the inflammatory reaction in the wall of your bowel can affect both your appetite and your ability to digest and absorb food.
Fistula or abscess- Inflammation from Crohn's disease may tunnel through the wall of the bowel into adjacent organs, such as the bladder or vagina, creating an abnormal connection called a fistula. This can also lead to an abscess, a swollen, pus-filled sore. The fistula may also tunnel out through your skin. A common place for this type of fistula is in the area around the anus. When this occurs, it's called perianal fistula.

Diagnosis:
Blood tests- Your doctor may suggest blood tests to check for anemia — a condition in which there aren't enough red blood cells to carry adequate oxygen to your tissues — or to check for signs of infection. Two tests that look for the presence of certain antibodies can sometimes help diagnose which type of inflammatory bowel disease you have, but not everyone with Crohn's disease or ulcerative colitis has these antibodies.
Colonoscopy- This test allows your doctor to view your entire colon using a thin, flexible, lighted tube with an attached camera. During the procedure, your doctor can also take small samples of tissue (biopsy) for laboratory analysis, which may help confirm a diagnosis.
Flexible sigmoidoscopy- In this procedure, your doctor uses a slender, flexible, lighted tube to examine the sigmoid, the last 2 feet of your colon. The test usually takes just a few minutes. It's somewhat uncomfortable, and there's a slight risk of perforating the colon wall. It may also miss problems higher up in your colon or in your small intestine.
Barium enema- This diagnostic test allows your doctor to evaluate your large intestine with an X-ray. Before the test, barium, a contrast dye, is placed into your bowel in an enema form. Sometimes, air also is added. The barium fills and coats the lining of the bowel, creating a silhouette of your rectum, colon and a portion of your small intestine.
Small bowel X-ray- This test looks at the part of the small bowel that can't be seen by colonoscopy. After you drink barium, X-ray pictures are taken of your small intestine. The test can help locate areas of narrowing or inflammation in the small bowel that are seen in Crohn's disease.
Computerized tomography (CT)- Sometimes you may have a CT scan, a special X-ray technique that provides more detail than a standard X-ray does. This test looks at the entire bowel as well as at tissues outside the bowel that can't be seen with other tests. Your doctor may order this scan to better understand the location and extent of your disease or to check for complications such as a partial blockages, abscesses or fistulas. Although not invasive, a CT scan exposes you to more radiation than a conventional X-ray does.

Capsule endoscopy- If you have signs and symptoms that suggest Crohn's disease but the usual diagnostic tests are negative, your doctor may perform capsule endoscopy. For this test you swallow a capsule that has a camera in it. The camera takes pictures, which are transmitted to a computer that you wear on your belt. The images are then downloaded, displayed on a monitor and checked for signs of Crohn's disease. Once it's made the trip through your digestive system, the camera exits your body painlessly in your stool.

Capsule endoscopy is generally very safe, but if you have a partial blockage in the bowel, there's a slight chance the capsule may become lodged in your intestine. Your doctor will try to minimize the chance of this by performing other diagnostic tests to look for a partial blockage before you have this procedure. If the camera does become lodged in the bowel, it may need to be surgically removed.

Treatment:
Anti-inflammatory drugs are often the first step in the treatment of inflammatory bowel disease. They include:

Sulfasalazine (Azulfidine)- Doctors have used this drug for many years to treat Crohn's disease. Although it can be effective in reducing symptoms of the disease, it has a number of side effects, including nausea, vomiting, heartburn and headache. Don't take this medication if you're allergic to sulfa medications.
Mesalamine (Asacol, Rowasa)- This medication tends to have fewer side effects than sulfasalazine has. You take it in tablet form or use it rectally in the form of an enema or suppository, depending on which part of your colon is affected.
Corticosteroids- Corticosteroids can help reduce inflammation anywhere in your body, but they have numerous side effects, including a puffy face, excessive facial hair, night sweats, insomnia and hyperactivity. More serious side effects include high blood pressure, type 2 diabetes, osteoporosis, bone fractures, cataracts and an increased susceptibility to infections. Long-term use of corticosteroids in children can lead to stunted growth.

Immune system suppressors are drugs which reduce inflammation, but they target your immune system rather than treating inflammation itself.
Azathioprine (Imuran) and mercaptopurine (Purinethol)- These are the most widely used immunosuppressants for treatment of inflammatory bowel disease. Although it can take up to three months for these medications to begin to work, they help reduce signs and symptoms of IBD in general and can heal fistulas from Crohn's disease in particular. If you're taking either of these medications, you'll need to follow up closely with your doctor and have your blood checked regularly to look for side effects.
Infliximab (Remicade)- This drug is specifically for adults and children with moderate to severe Crohn's disease who don't respond to or can't tolerate other treatments. It works by neutralizing a protein produced by your immune system known as tumor necrosis factor (TNF). Infliximab finds TNF in your bloodstream and removes it before it causes inflammation in your intestinal tract and contributes to the formation of fistulas.
Methotrexate (Rheumatrex)- This drug, normally used to treat cancer, is sometimes used for people with Crohn's disease who don't respond well to other medications. It starts working in about eight to 10 weeks. Short-term side effects include nausea, fatigue and diarrhea, and rarely, it can cause allergic pneumonia.
Cyclosporine (Neoral, Sandimmune)- This potent drug, which is most often used to help heal Crohn's-related fistulas, is normally reserved for people who don't respond well to other medications. Cyclosporine begins working in one to two weeks — more quickly than less toxic drugs — but it has the potential for serious side effects, such as kidney and liver damage, high blood pressure, seizures, fatal infections and an increased risk of lymphoma.

Antibiotics can heal fistulas and abscesses in people with Crohn's disease. Researchers also believe antibiotics help reduce harmful intestinal bacteria and directly suppress the intestine's immune system, which can trigger symptoms. Frequently prescribed antibiotics include:
Metronidazole (Flagyl)- Once the most commonly used antibiotic for Crohn's disease, metronidazole can sometimes cause serious side effects, including numbness and tingling in your hands and feet and, occasionally, muscle pain or weakness. If these effects occur, stop the medication and call your doctor. Other side effects include nausea, a metallic taste in your mouth, headache, dizziness and loss of appetite. Avoid alcoholic beverages while taking this medication because a severe reaction may result.
Ciprofloxacin (Cipro)- This drug, which improves symptoms in some people with Crohn's disease, is now generally preferred to metronidazole. Ciprofloxacin may cause fainting, an irregular heartbeat, abdominal pain, diarrhea, fatigue and, rarely, tendon problems.