Inflammatory bowel disease is a group of two diseases: ulcerative colitis and Crohn's disease. These chronic illnesses can inflame the gastrointestinal tract, causing bloody diarrhea, abdominal pain, and weight loss. Ulcerative colitis can affect the entire large intestine or the rectum. Crohn's disease mainly affects short segments of both the small and large intestine.
Crohn’s disease is an ongoing disorder 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 swelling extends deep into the lining of the affected organ. The swelling can cause pain and can make the intestines empty frequently, resulting in diarrhea.
Crohn’s disease affects men and women equally and seems to run in some families. About 20% of people with Crohn’s disease have a blood relative with some form of inflammatory bowel disease, most often a brother or sister and sometimes a parent or child. Crohn’s disease can occur in people of all age groups, but it is more often diagnosed in people between the ages of 20 and 30. People of Jewish heritage have an increased risk of developing Crohn’s disease, and blacks are at decreased risk for developing Crohn’s disease.
The cause(s) of inflammatory bowel disease is not known. However people believe that it may be genetically linked since IBD is known to run in families.
An environmental cause is also believed to play a role in developing Crohn's disease because it is most often occurs in people who smoke, are residents of Northern European countries and live in urban areas.
Other researchers speculate that the disease may be caused by an infection or virus.
Still others believe that the body's immune system is reacting to unidentified or unknown antigens. This antigen would cause the immune system to respond inappropriately against normal intestinal tissue, resulting in chronic inflammation.
Measles, mumps, or rubella virus infection is not known to cause IBD. The virus that causes measles infects the respiratory system and then spreads to lymphatic tissue (an important part of the immune system). During the acute infection, lymph cells in the gastrointestinal tract are infected, but whether this causes chronic inflammation is highly questionable.
One theory speculates that measles virus may persist in the intestine in certain individuals and later trigger a chronic inflammatory infection; however, this has not been proven. Because the measles, mumps, and rubella (MMR) vaccine contains a very weak live measles virus it has been suggested that the vaccine could cause an inflammatory process in the intestine. This theory has not been proven and is speculative.
The most common symptoms of Crohn’s disease are abdominal pain, often in the lower right area, and diarrhea. Rectal bleeding, weight loss, arthritis, skin problems, and fever may also occur. Bleeding may be serious and persistent, leading to anemia. Children with Crohn’s disease may suffer delayed development and stunted growth. The range and severity of symptoms varies.
A thorough physical exam and a series of tests may be required to diagnose Crohn’s disease or ulcerative colitis.
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, before X-rays are taken.
The doctor may also do a visual exam of the colon by performing either a sigmoidoscopy or a colonoscopy. For both of these tests, the doctor inserts a long, flexible, lighted tube linked to a computer and TV monitor into the anus.
The doctor may also do a biopsy, which involves taking a sample of tissue from the lining of the intestine to view with a microscope.
The most common complication is blockage of the intestine. Blockage occurs because the disease tends to thicken the intestinal wall with swelling and scar tissue, narrowing the passage.
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.
Nutritional complications are common in Crohn’s disease. 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.
Ulcerative colitis is a disease that causes inflammation and sores, called ulcers, in the lining of the rectum and colon. Ulcers form where inflammation has killed the cells that usually line the colon, then bleed and produce pus. Inflammation in the colon also causes the colon to empty frequently, causing diarrhea.
Ulcerative colitis can occur in people of any age, but it usually starts between the ages of 15 and 30, and less frequently between 50 and 70 years of age. It affects men and women equally and appears to run in families, with reports of up to 20% of people with ulcerative colitis having a family member or relative with ulcerative colitis or Crohn’s disease. A higher incidence of ulcerative colitis is seen in whites and people of Jewish descent.
Ulcerative colitis may also cause problems such as arthritis, inflammation of the eye, liver disease, and osteoporosis. It is not known why these problems occur outside the colon. Scientists think these complications may be the result of inflammation triggered by the immune system. Some of these problems go away when the colitis is treated.
Many theories exist about what causes ulcerative colitis. People with ulcerative colitis have abnormalities of the immune system, but doctors do not know whether these abnormalities are a cause or a result of the disease. The body’s immune system is believed to react abnormally to the bacteria in the digestive tract.
Ulcerative colitis is not caused by emotional distress or sensitivity to certain foods or food products, but these factors may trigger symptoms in some people. The stress of living with ulcerative colitis may also contribute to a worsening of symptoms.
Treatment may include drugs, nutrition supplements, surgery, or a combination of these options. 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. Many of the treatments are used for both conditions.
Someone with inflammatory bowel disease may need medical care for a long time, with regular doctor visits to monitor the condition.
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 corticosteriods—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.
Infliximab (Remicade). This drug is the first of a group of medications that blocks the body’s inflammation response. The 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. Infliximab, the first treatment approved specifically for Crohn’s disease, is a TNF substance.
Antibiotics. In inflammatory bowel disease antibiotics are used to treat bacterial overgrowth in the small intestine caused by stricture, fistulas, or prior surgery. For this common problem, the doctor may prescribe one or more of the following antibiotics: ampicillin, sulfonamide, 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.
Two-thirds to three-quarters of patients with Crohn’s disease will require surgery at some point in their lives. About 25% to 40% of ulcerative colitis patients must eventually have their colons removed because of massive bleeding, severe illness, rupture of the colon, or risk of cancer.
Surgery becomes necessary when medications can no longer control symptoms. Surgery is used either 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’s disease, but it is not a cure. Surgery does not eliminate the disease as inflammation tends to return to the area next to where the diseased intestine was removed.
In ulcerative colitis, surgery maybe needed to remove the colon and/or rectum.
About 5% of people with ulcerative colitis develop colon cancer. The risk of cancer increases with the duration of the disease and how much the colon has been damaged. For example, if only the lower colon and rectum are involved, the risk of cancer is no higher than normal. However, if the entire colon is involved, the risk of cancer may be as much as 32 times the normal rate.
Sometimes precancerous changes occur in the cells lining the colon. These changes are called "dysplasia." People who have dysplasia are more likely to develop cancer than those who do not. Doctors look for signs of dysplasia when doing a colonoscopy or sigmoidoscopy and when examining tissue removed during these tests.
According to the 2002 updated guidelines for colon cancer screening, people who have had IBD throughout their colon for at least eight years and those who have had IBD in only the left colon for 12 to 15 years should have a colonoscopy with biopsies every 1 to 2 years to check for dysplasia. Such screening has not been proven to reduce the risk of colon cancer, but it may help identify cancer early. These guidelines were produced by an independent expert panel and endorsed by numerous organizations, including the American Cancer Society, the American College of Gastroenterology, the American Society of Colon and Rectal Surgeons, and the Crohn’s & Colitis Foundation of America.