Inflammatory Bowel Disease

Crohn's and a related disease, ulcerative colitis, are the two main disease categories that belong to a larger group of illnesses called inflammatory bowel disease (IBD). Because the symptoms of these two illnesses are so similar, it is sometimes difficult to establish the diagnosis definitively.

It is estimated that as many as one million Americans have IBD — with that number evenly split between Crohn's disease and ulcerative colitis. Males and females appear to be affected equally.

Both illnesses do have one strong feature in common. They are marked by an abnormal response by the body's immune system. The immune system is composed of various cells and proteins. Normally, these protect the body from infection. In people with IBD, however, the immune system reacts inappropriately. Mistaking food, bacteria, and other materials in the intestine for foreign or invading substances, it launches an attack. In the process, the body sends white blood cells into the lining of the intestines, where they produce chronic inflammation. These cells then generate harmful products that ultimately lead to ulcerations and bowel injury. When this happens, the patient experiences the symptoms of IBD.

Although Crohn's disease most commonly affects the end of the small intestine (the ileum) and the beginning of the large intestine (the colon), it may involve any part of the GI tract. In ulcerative colitis, on the other hand, the GI involvement is limited to the colon.

Although considerable progress has been made in IBD research, investigators do not yet know what causes this disease. Studies indicate that the inflammation in IBD involves a complex interaction of factors: the genes the patient has inherited, the immune system, and something in the environment. Foreign substances (antigens) in the environment may be the direct cause of the inflammation, or they may stimulate the body's defenses to produce an inflammation that continues without control. Researchers believe that once the IBD patient's immune system is "turned on," it does not know how to properly "turn off" at the right time. As a result, inflammation damages the intestine and causes the symptoms of IBD. That is why the main goal of medical therapy is to help patients regulate their immune system better.

IBD tends to run in families, so we know that genes definitely play a role in the IBD picture. Studies have shown that about 20 to 25 percent of patients may have a close relative with either Crohn's or ulcerative colitis. If a person has a relative with the disease, his or her risk is about 10 times greater than that of the general population. If that relative happens to be a brother or sister, the risk is 30 times greater.

Researchers have been working actively for some time to find a link to specific genes that control the transmission of this illness. Recently, an important breakthrough was achieved when the first gene for Crohn's disease was identified by a team of IBD investigators. The researchers were able to pick out an abnormal mutation or alteration in a gene known as Nod2. This mutation, which limits the ability to fight bacteria, occurs twice as frequently in Crohn's patients as in the general population. At this time, no method is available to screen patients for this gene. There is also no way to predict which, if any, family members will develop Crohn's disease. The data further suggests that more than one gene may be involved. Because of technological advances, though, researchers may soon close in on those genes.

IBD also appears to affect certain ethnic groups more than others. For example, American Jews of European descent are four to five times more likely to develop IBD than the general population. IBD has long been thought of as a disease predominantly affecting whites; the prevalence rate (the number of people with a disease at a given time) among whites is 149 per 100,000. However, there has been a steady increase in reported cases of both Crohn's disease and ulcerative colitis among African Americans. The prevalence rates among Hispanics and Asians are lower than those for whites and African Americans.

Persistent diarrhea (loose, watery, or frequent bowel movements), crampy abdominal pain, fever, and, at times, rectal bleeding: These are the hallmark symptoms of IBD, but they vary from person to person and may change over time. However, the disease is not always limited to the GI tract; it can also affect the joints, eyes, skin, and liver. Children who have Crohn's disease may suffer delayed growth and sexual development.

There is no single test that can establish the diagnosis of IBD with certainty and a combination of information from the patient's history and physical exam, laboratory tests, X-rays, and findings on endoscopy and pathology tests allows a definitive diagnosis. Because Crohn's disease often mimics other conditions and symptoms may vary widely, it may take some time to arrive at the correct diagnosis.

Because there is no cure for IBD, the goal of medical treatment is to suppress the inflammatory response. This step accomplishes two important goals: The first goal is to induce remission by allowing the intestinal tissue to heal and it also relieves the symptoms of fever, diarrhea, and abdominal pain. Once the symptoms are brought under control, next step is maintenance of remission and medical therapy is used long-term to decrease the frequency of disease flares and to maintain remission.

There is no evidence that any particular foods cause or contribute to Crohn's disease or other types of IBD. Once the disease has developed, however, paying special attention to diet may help reduce symptoms, replace lost nutrients, and promote healing.

Good nutrition is essential for anyone who has a chronic disease, but it is especially important in IBD for several reasons. First, the appetite is often reduced in people with IBD. Second, chronic diseases tend to increase the energy or caloric needs of the body. This is particularly true during episodes of disease "flares." And third, IBD is associated with diarrhea and poor absorption or dietary protein, fat, carbohydrates, and water. All these symptoms rob the body of fluids, nutrients, and a wide variety of vitamins and minerals. Restoring and maintaining proper nutrition is a vital part of the medical management of IBD.

In one-quarter to one-third of patients with ulcerative colitis, medical therapy is not completely successful or complications arise. Under these circumstances, surgery may be considered. This operation involves the removal of the colon (colectomy). Unlike Crohn's disease, which can recur after surgery, ulcerative colitis is usually "cured" once the colon is removed. However, surgery comes with its own set of problems.

Because body and mind are so closely interrelated, emotional stress can influence the course of IBD — or, for that matter, any other chronic illness. Although formal psychotherapy is generally not necessary, some patients are helped considerably by speaking with a therapist who is knowledgeable about IBD or about chronic illness in general. Crohn's and Colitis Foundation (CCFA) offers local support groups to help patients and their families cope with IBD.

Most people with IBD lead successful and productive lives, even though they may be hospitalized from time to time, or need to take medications. In between flare-ups of the disease, many individuals feel well and may be relatively free of symptoms. But again, everyone is different, and it is up to you and your physician to find the treatment that works best for you.

Even though there is no cure at this time, research and education programs already have improved the health and quality of life of people with IBD.

Dr. Nuzhat Iqbal is a board certified gastroenterologist. She joined Longmont Clinic in October 2003. She can be reached at 720-494-3123.