Inflammatory Bowel Diseases

Introduction

If you have either of two autoimmune problems that result in episodes of inflammation within the digestive tract, you have inflammatory bowel disease (IBD). The two types of IBD are Crohn's disease and ulcerative colitis. While these two conditions are separate illnesses, it can be difficult to tell them apart when a person first develops IBD. The term "inflammatory bowel disease" is used to describe both illnesses, without differentiating between them.

With proper treatment (which includes medications), either type of IBD can be controlled. Occasionally, surgery is required for complications or for severe cases. Symptoms typically come and go over many years, with flare-ups and dormant periods. Most people who have IBD have symptoms that are limited to the digestive tract. Occasionally, IBD is accompanied by arthritis.

What are the inflammatory bowel diseases?

Ulcerative colitis causes inflammation within the rectum (known as "proctitis") and the colon ("colitis"). The inflammation irritates the inner lining of these areas of bowel, but it does not spread into the muscle layers deeper within the intestinal wall. Crohn's disease, by contrast, can cause inflammation or complications anywhere from the mouth to the rectum, and the inflammation can injure the full thickness of the intestinal wall.

Inflammation from ulcerative colitis can result in diarrhea and in exposed sores ("ulcers") in the bowel lining. Because inflammation is deeper, Crohn's disease can cause these problems as well as other complications. For example, Crohn's disease can cause abscesses (pus pockets), ruptures of the intestine, or an unusual tunnel-like connection ("fistula") between two areas of bowel. In people with Crohn's disease, ulcers may occur in any area of the digestive tract, including the mouth or the esophagus, as well as the digestive tract within the abdomen.

What causes IBD?

The exact cause of either Crohn's disease or ulcerative colitis is not known. Each form of IBD can run in families, and at least 10 percent of people with either Crohn's disease or ulcerative colitis can identify a family member who has their condition. Although these illnesses are not restricted to any ethnic group, forms of IBD are especially common in people of Jewish descent. It is believed that an inherited gene makes some people with a family history prone to developing the disease. Since most family members do not get the disease, we know that a separate factor also must occur to trigger IBD. Most researchers suspect that an intestinal infection or injury may be responsible for activating your immune system and initiating a disease within the IBD family. Some experts speculate that this trigger might even occur in infancy, causing symptoms years later.

What are the symptoms?

General symptoms include abdominal pain, diarrhea and/or constipation, and possibly rectal bleeding, weight loss, fever, nausea or vomiting.

Episodes of abdominal pain, nausea, vomiting and diarrhea related to inflammatory bowel disease can be difficult to distinguish from simple viral infections or other benign conditions, such as irritable bowel syndrome. Occasionally IBD is misdiagnosed until symptoms become prominent.

How is it finally diagnosed?

A physician uses your medical history and the results of a physical exam to decide if there are other potential causes of your symptoms. The doctor may order blood tests or stool examinations to help in the diagnosis. X-ray tests, such as an upper GI series or barium enema, might be ordered to help look for abnormalities of the small intestines or colon. The only way to make a definite diagnosis is by performing camera inspection of the inside of your bowel (a colonoscopy or flexible sigmoidoscopy). These tests provide an inside view of your colon and allow for biopsies of the inner lining of the colon. The biopsies are viewed under a microscope to look for the characteristic inflammation of IBD. To make the diagnosis of Crohn's disease, an upper endoscopy (called esophagogastroduodenoscopy, or EGD)may be necessary.

Usually, your symptoms and a camera inspection of your bowel is enough to guide your doctors in determining what type of IBD you have. In some cases, antibody tests can help doctors decide between a diagnosis of ulcerative colitis and Crohn's disease. Although useful in telling one type of IBD from another, these tests can't be used to determine if you have IBD in the first place.

How is IBD treated?

Treatments for IBD are directed against the inflammation in the bowel. Medicines can control flare-ups and prevent recurrences during symptom-free periods. It is important to control IBD inflammation in order to prevent complications.

Drugs work by calming down the immune system's attack on the bowel. Most people are treated with several different medicines; medicines may be combined or used at different times. The most common types of treatments are anti-inflammatory medicines in a drug family known as five-amino salicylic acids; steroids; antibiotics; and immune-system modulators such as mercaptopurine and azathioprine. If symptoms are limited to the bowel near the rectum, some of these medications can be given rectally, through enemas. By taking medicines in the form of an enema, you can avoid some of the side effects that occur when the medications are taken in pill form by mouth. Sometimes, dietary changes help symptoms. Evidence indicates that fish-oil capsules are beneficial in treating ulcerative colitis.

It is possible to "cure" the symptoms of ulcerative colitis by removing the entire colon surgically. This treatment is used only in severe cases. By contrast, because Crohn's disease can affect areas in the digestive tract above the colon and rectum, colon surgery cannot cure this disease. When surgery is required in Crohn's disease, the purpose usually is to correct complications.

When is it necessary to remove a part of the bowel?

Surgical removal of a portion of intestine is occasionally needed if symptoms or complications can't be controlled with medicines. In severe cases, surgical removal of the colon may also be recommended for cancer prevention (see below).

If I have colitis, am I likely to get colon cancer?

In some patients with IBD, the ongoing cycle of inflammation, scarring and healing that takes place in the bowel can eventually trigger a cancer. The risk increases with the number of years and the severity of inflammatory bowel disease. For this reason, patients with inflammatory bowel disease should be screened for colon cancer with a colonoscopy test. Screening should be performed at regular intervals.

Because cancer risk is substantially increased, surgery may be recommended as a way to prevent colon cancer if you have had Crohn's disease or ulcerative colitis for eight years or more and if the disease involved an extensive length of your colon.

If my colon is removed, will I have to have an ileostomy, or "bag"?

For the small number of people with IBD who require removal of part or all of the colon, a surgery referred to as the "anal pull-through" enables most individuals to avoid having a long-term ileostomy. With an ileostomy, once the colon is removed, the small intestine is attached to an opening in the abdominal wall, and a small waste-collection bag is worn on the outside of the abdomen to collect the stool. In the "anal pull-through" procedure, the small intestine is attached directly to the lower part of the rectum, and stool continues to be passed through the natural anus. People with no colon may have about six liquid bowel movements per day because less liquid is removed from the stool during digestion.

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