Crohn's Disease

Crohn's disease is a chronic illness that causes inflammation of the digestive tract, also referred to as the gastrointestinal (GI) tract. Crohn's disease can affect any area of the GI tract, from the mouth to the anus, but it most commonly affects the lower part of the small intestine, called the ileum. The most common symptoms are pain in the abdomen and diarrhea. Sometimes Crohn's disease can be difficult to diagnose because the symptoms can be very similar to other illness of the GI tract such as irritable bowel syndrome or ulcerative colitis

Contents 1 Other Names 2 Symptoms 3 Causes 4 Diagnosis 4.1 Exams And tests 5 Treatment 5.1 Medications 5.2 Other therapies 6 Living with Crohn's Disease 6.1 The effects of stress 6.2 Getting pregnant 7 Chances of Developing Crohn's Disease 7.1 Genetics 7.2 Race and ethnicity 7.3 Environment 8 Related Problems 8.1 Complications 9 Research 10 Controversy 11 Related Video 12 References 13 External Links

Other Names

• regional enteritis
• granulomatous ileitis
• ileocolitis
• terminal ileitis

Symptoms

The range and severity of symptoms in Crohn's disease can be quite varied. The most common symptoms of Crohn's disease include the following:

• crampy pain in the abdomen, often in the lower right area
• persistent diarrhea (loose, watery, or frequent bowel movements)
• fever

Other symptoms that can be seen:

• rectal bleeding which may be serious and persistent, leading to anemia
• constipation
• nausea
• loss of appetite
• weight loss
• tiredness
• joint pains
• skin problems
• stunted growth and delayed development in children
• pain in the rectal area due to fissures (tear in the anal lining)

Because Crohn's disease is a chronic illness, symptoms can come and go. Some people will experience remission, which is relatively asymptomatic, and occasional flares, where the symptoms become especially problematic.

Causes

The cause of Crohn's disease is still unknown. The immune system is made of cells and different proteins that protect people from infection. The most popular theory as to the cause of Crohn's disease is that the body's immune system reacts abnormally to foreign substances. This can lead to an 'over-active' immune system that causes ongoing inflammation in the GI tract. Some of these foreign substances may themselves cause inflammation in the GI tract. Some scientists think that a protein produced by the immune system, called tumor necrosis factor (TNF), may be a possible cause for the inflammation associated with Crohn's disease.

Scientists do not know if the over-active immune system in people with Crohn's disease is a cause, or a result, of the disease. Research shows that the inflammation seen in the GI tract of people with Crohn's disease involves several factors: the genes the person has inherited, the immune system itself, and the environment. How these factors interact to cause Crohn's disease is not fully understood.

Diagnosis

The diagnosis of Crohn's disease is usually made through close examination of the patient's medical history, their genetic background, the type and severity of symptoms, and through physical examination and laboratory tests.

Exams And tests

A thorough physical exam and a series of tests may be required to diagnose Crohn’s disease as this disease is often misdiagnosed or confused with ulcerative colitis and other related intestinal disorders.

Blood tests may be done to check for anemia, which could indicate bleeding in the intestines. Blood tests may also uncover a high white blood cell count, which is a sign of inflammation somewhere in the body. By testing a stool sample, the doctor can tell if there is bleeding or infection in the intestines.

The doctor may do an upper GI series to look at the small intestine. For this test, the person drinks barium, a chalky solution that coats the lining of the small intestine; x-rays of the abdomen are then taken. The barium shows up white on x-ray film, revealing inflammation or other abnormalities in the intestine. If these tests show Crohn's disease, more x-rays of both the upper and lower digestive tract may be necessary to see how much of the GI tract is affected by the disease.

It is often necessary to perform a sigmoidoscopy or a colonoscopy to confirm the diagnosis of Crohn's disease and to determine the extent of disease. For both of these test, a flexible tube is inserted into the anus. This tube allows the doctor to visually inspect the lining of the lower part of the large intestines in the case of sigmoidoscopy, or the entire large intestines in the case of colonoscopy. The doctor will be able to look for areas of inflammation or bleeding in the large intestines during this exam, and will be able to perform a small biopsy of the colon if this is needed.

Treatment

Treatment may include drugs, nutrition supplements, surgery, or a combination of these options. The goals of treatment are to control inflammation, correct nutritional deficiencies, and relieve symptoms like abdominal pain, diarrhea, and rectal bleeding. Treatment for Crohn's disease depends on the location and severity of disease, complications, and the person’s response to previous medical treatments when treated for reoccurring symptoms.

Some people have long periods of remission, sometimes years, when they are free of symptoms. However, the disease usually recurs at various times over a person’s lifetime. This changing pattern of the disease means one cannot always tell when a treatment has helped. Predicting when a flare may occur or when symptoms will return is not possible.

Medications

Anti-Inflammation Drugs. Most people are first treated with drugs containing mesalamine, a substance that helps control inflammation. Sulfasalazine is the most commonly used of these drugs. Patients who do not benefit from it or who cannot tolerate it may be put on other mesalamine-containing drugs, generally known as 5-ASA agents, such as Asacol, Dipentum, or Pentasa. Possible side effects of mesalamine-containing drugs include nausea, vomiting, heartburn, diarrhea, and headache.

Cortisone or Steroids. Cortisone drugs and steroids—called corticosteroids—provide very effective results. Prednisone is a common generic name of one of the drugs in this group of medications. In the beginning, when the disease it at its worst, prednisone is usually prescribed in a large dose. The dosage is then lowered once symptoms have been controlled. These drugs can cause serious side effects, including greater susceptibility to infection.

Immune System Suppressors. Drugs that suppress the immune system are also used to treat Crohn's disease. Most commonly prescribed are 6-mercaptopurine or a related drug, azathioprine. Immunosuppressive agents work by blocking the immune reaction that contributes to inflammation. These drugs may cause side effects like nausea, vomiting, and diarrhea and may lower a person’s resistance to infection. When patients are treated with a combination of corticosteroids and immunosuppressive drugs, the dose of corticosteroids may eventually be lowered. Some studies suggest that immunosuppressive drugs may enhance the effectiveness of corticosteroids.

Infliximab (Remicade). This drug is the first of a group of medications that blocks the body’s inflammation response. In 1998, the U.S. Food and Drug Administration (FDA) approved the drug for the treatment of moderate to severe Crohn's disease that does not respond to standard therapies (mesalamine substances, corticosteroids, immunosuppressive agents) and for the treatment of open, draining fistulas. In 2002, the FDA approved infliximab for maintaining remissions. The drug is an antibody that blocks the immune system's production of tumor necrosis factor (TNF), a substance that promotes inflammation.

Antibiotics. Antibiotics are used to treat bacterial overgrowth in the small intestine caused by strictures, fistulas, or prior surgery. For this common problem, the doctor may prescribe one or more of the following antibiotics: ampicillin, sulfonamide, a cephalosporin, tetracycline, or metronidazole.

Anti-Diarrheal and Fluid Replacements. Diarrhea and crampy abdominal pain are often relieved when the inflammation subsides, but additional medication may also be necessary. Several antidiarrheal agents could be used, including diphenoxylate, loperamide, and codeine. Patients who are dehydrated because of diarrhea will be treated with fluids and electrolytes.

Helminths (intestinal worms) have been with humans throughout our evolution as a species; their use as a therapy for Crohn's disease is a relatively new option that shows considerable promise.^[1] The key observation that led to initial clinical trials was that persons living in areas with high rates of intestinal parasite infestation were much less likely to have Crohn's disease, suggesting that worms in the intestine inhibit the host immune response in ways that allow long-term colonization. One consequence of this local immunosuppression may be a decreased risk of diseases such as Crohn's disease and inflammatory bowel disease. As a therapy for Crohn's disease, the species of worm that shows the most promise is Trichuris suis, the pig whipworm; the patient is asked to swallow eggs (as opposed to adult worms) that travel to the intestine and hatch, providing local immunosuppression. The whipworms are only able to set up long-term infestations in pigs, and so are relatively rapidly eliminated from humans; the immunosuppression is much more long-lasting and provides significant benefit in the majority of patients.

Other therapies

Surgery. Most patients with Crohn’s disease will require surgery at some point in their lives to relieve symptoms that do not respond to medical therapy or to correct complications such as blockage, perforation, abscess, or bleeding in the intestine. Surgery to remove part of the intestine can help people with Crohn disease, but it is not a cure. Surgery does not eliminate the disease, and it is not uncommon for people with Crohn Disease to have more than one operation, as inflammation tends to return to the area next to where the diseased intestine was removed.

Nutritional supplementation. Because Crohn's disease is an inflammation of parts of the GI tract, the intestines in someone with Crohn's may not be able to absorb enough nutrients to maintain health. In such cases, nutritional supplements may be recommended, especially for children whose growth has been slowed. Special high-calorie liquid formulas are sometimes used for this purpose. A small number of people with Crohn's disease may need to be fed by intravenously for a brief time through a small tube inserted into the vein of the arm. This procedure can help people who need extra nutrition temporarily, those whose intestines need to rest, or those whose intestines cannot absorb enough nutrition from food. There are no known foods that cause Crohn’s disease. However, when people are suffering a flare in disease, foods such as bulky grains, hot spices, alcohol, and milk products may increase diarrhea and cramping.

Living with Crohn's Disease

The effects of stress

There is no evidence that stress causes Crohn’s disease. However, people with Crohn’s disease sometimes feel increased stress in their lives from having to live with a chronic illness. Some people with Crohn’s disease also report that they experience a flare in disease when they experience a stressful event or situation. For people who find there is a connection between their stress level and a worsening of their symptoms, using relaxation techniques, such as slow breathing, and taking special care to eat well and get enough sleep, may help them feel better.

Getting pregnant

Research has shown that the course of pregnancy and delivery is usually not impaired in women with Crohn’s disease. Even so, women with Crohn’s disease should discuss the matter with their doctors before pregnancy. Most children born to women with Crohn’s disease are unaffected. Children who do get the disease are sometimes more severely affected than adults, with slowed growth and delayed development in some cases.

Chances of Developing Crohn's Disease

Genetics

Inflammatory bowel disease (IBD), which includes Crohn's disease and ulcerative colitis, tends to run in families. If a person has a relative with IBD, they have about a 10-times greater risk of getting IBD than the general public.

Researcher have been looking for genes that may increase the risk of development of IBD and Crohn's disease. There is some evidence that an abnormal gene called NOD2 occurs twice as frequently in people with Crohn's disease than in the general public. However, there currently is no test that can determine whether a person has the abnormal form of the gene or whether Crohn's disease will develop.

Race and ethnicity

Inflammatory bowel disease in general appears to occur more frequently in certain ethnic groups for reasons that are poorly understood. For example, American Jews of european descent are four to five times more likely to develop IBD than the general public. In addition, IBD has tended to affect primarily white people, but the rate of occurrence in African Americans seems to be increasing. The occurrence of disease in Hispanic and Asian populations is much less than in whites and African Americans.

Environment

Crohn's disease (and IBD) tends to occur more often in developed countries and is found predominately in the United States and Europe. It is also reportedly more common in urban areas than rural. Reasons for this distribution are unknown, but it does suggest an environmental link to the development of the disease.

Related Problems

Complications

The most common complication of Crohn's disease is blockage of the intestine. This can occur because the disease tends to thicken the intestinal wall with swelling and scar tissue which often leads to narrowing of the passageway of the colon and blockage. Crohn’s disease may also cause sores, or ulcers, that tunnel through the affected area into surrounding tissues, such as the bladder, vagina, or skin. The areas around the anus and rectum are often involved. The tunnels, called fistulas, are a common complication and often become infected. Sometimes fistulas can be treated with medicine, but in some cases they may require surgery. In addition to fistulas, small tears called fissures may develop in the lining of the anus.

Nutritional complications are common in Crohn’s disease. Deficiencies of proteins, calories, and vitamins are well documented. These deficiencies may be caused by inadequate dietary intake, intestinal loss of protein, or poor absorption, also referred to as malabsorption.

Other complications associated with Crohn’s disease include arthritis, skin problems, inflammation in the eyes or mouth, kidney stones, gallstones, or other diseases of the liver and biliary system. Some of these problems resolve during treatment for disease in the digestive system, but some must be treated separately.

Research

The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) conducts and supports research into many kinds of digestive disorders, including Crohn’s disease. Several clinical trials are currently evaluating the efficacy and safety of different therapies for the treatment of Crohn’s disease. For a complete listing of trials being conducted go here: Crohn's Disease Trials .

Controversy

Some researchers believe Crohn disease is caused by a bacterial infection due to Mycobacterium avium subspecies paratuberculosis.^[2] Mycobacterium avium subspecies paratuberculosis causes Johne's disease in cattle and other animals. Johne's disease has similar features to Crohn and irritable bowel syndrome in humans. The evidence is so far inconclusive and several researchers disagree with a mycobacterial cause for Crohn disease.

Related Video

In this NHSChoices video, Dr. Neil Borley, colorectal surgeon at Cheltenham General Hospital, discusses the symptoms and treatment options for Crohn's disease, an inflammation of the gut:

References

1. ↑ Summers RW, Elliott DE, Urban JF Jr, Thompson R, Weinstock JV. Trichuris suis therapy in Crohn's disease. Gut. 2005 Jan;54(1):87-90. Abstract | Full Text | PDF
2. ↑ Scanu AM, Bull TJ, Cannas S, Sanderson JD, Sechi LA, Dettori G, Zanetti S, Hermon-Taylor J. Mycobacterium avium subspecies paratuberculosis infection in cases of irritable bowel syndrome and comparison with Crohn disease and Johne's disease: common neural and immune pathogenicities. J Clin Microbiol. 2007 Dec;45(12):3883-90. Abstract | Full Text

External Links

Crohn's & Colitis Foundation of America

Reach Out for Youth with Ileitis and Colitis, Inc.

United Ostomy Association, Inc.

National Association for Colitis and Crohn's disease

National Digestive Diseases Information Clearinghouse (NDDIC): Crohn Disease

Free Presentations of the 4th Congress of ECCO - the European Crohn`s and Colitis Organization [1]