Ulcerative Colitis: Inflammatory Bowel Disease

Description

Alternative Names

Diagnosis

The physician will take a history and perform a thorough physical examination. The disease is particularly difficult to diagnose in children, in whom IBD may be mistaken for an infection or even depression if other characteristic symptoms, such as bloody diarrhea and weight loss, are not present. Slow growth may be a key feature in making a diagnosis, particularly of Crohn's disease, in children.

A number of laboratory tests may be taken, such as the following:

• Blood tests are used for various purposes. An increased number of white blood cells may indicate the presence of inflammation. Blood tests are used to determine the presence of anemia and to measure liver enzymes. (They are abnormal in about 3% of ulcerative colitis patients.) New blood tests that measure certain antibodies may make it easier to differentiate Crohn's disease from ulcerative colitis in children.
• A stool sample is taken and examined for blood, infectious agents, or both.

Blood is drawn from a vein (venipuncture), usually from the inside of the elbow or the back of the hand. A needle is inserted into the vein, and the blood is collected in an air-tight vial or a syringe. Preparation may vary depending on the specific test.

Imaging Procedures Used for Diagnosis

Endoscopic Procedures. Flexible sigmoidoscopy and colonoscopy are endoscopic procedures. They are important in the diagnosis of both ulcerative colitis and Crohn's disease. Both procedures involve snaking a fiberoptic tube called an endoscope through the rectum to view the lining of the colon. The physician may also insert instruments through it to remove a tissue sample for a biopsy.

• Sigmoidoscopy, which is used to examine the rectum and left (sigmoid) colon, lasts about 10 minutes and is done without sedation. It may be mildly uncomfortable, but it is not painful. Ulcerative colitis almost always involves the lower left colon and rectum and is diagnosed using sigmoidoscopy. The physician usually observes an evenly distributed inflamed surface lining the intestine, and the bowel wall bleeds easily when touched with a swab.
• Colonoscopy allows a view of the entire colon and requires a sedative, but it is still performed on an outpatient basis. It is important in differentiating between Crohn's disease and ulcerative colitis and in screening for colon cancer.

The procedures may help the physician to distinguish between ulcerative colitis and Crohn's disease, as well as other diseases. A variation called chromoendoscopy uses a blue stain during the process to reveal fine details on the intestinal lining. It might prove to be useful for identify areas that may be precancerous and need to be biopsied.

X-rays and Barium Enema. The double-contrast barium enema, which uses an x-ray image, is less expensive than a colonoscopy for viewing the entire colon. Although not as accurate as colonoscopy, it is very valuable in diagnosing both Crohn's disease and ulcerative colitis in early stages. It should be noted that in patients with active ulcerative colitis, this procedure increases the risk for toxic megacolon.

Click the icon to see a depiction of the barium enema procedure.

X-rays of the abdomen are also useful when a patient has a severe attack of ulcerative colitis. In such cases, the edges of the colon are swollen and irregular. X-rays may also reveal thickened walls and other signs of severity.

Ultrasound. Intestinal wall ultrasound is proving to be useful for identifying the extent and severity of Crohn's disease. Although it is unclear if ultrasound is useful for an initial diagnosis, one study indicated that, when used by experienced professionals, it is effective for identifying Crohn's disease or ulcerative colitis.

Other Imaging Procedures. Magnetic resonance spectroscopy (MRS) is a variant of magnetic resonance imaging (MRI) that may prove to be useful for differentiating between Crohn's disease and ulcerative colitis.

Computed tomography (CT) scans may be useful for determining the extent of the disease on the intestine and for detecting abscesses and other complications of advanced IBD.

A promising experimental technique called virtual colonoscopy allows three-dimensional imaging of the colon without using invasive instruments. The procedure involves pumping air into the colon and scanning the intestine using computed tomography (CT) or magnetic resonance imaging (MRI). It is very safe, requires no sedation, and takes only about 10 minutes.

Ruling Out Diseases Resembling Inflammatory Bowel Disease

Irritable Bowel Syndrome. Irritable bowel syndrome (IBS), also known as spastic colon, functional bowel disease, and spastic colitis, causes many of the same symptoms as inflammatory bowel disease. Bloating, diarrhea, constipation, and abdominal cramps are all symptoms of IBS. Irritable bowel syndrome is not caused by inflammation, however, and no fever or bleeding occurs. Behavioral therapy may be helpful in treating IBS. (No psychologic therapy improves inflammatory bowel disease.)

Microscopic Colitis. Microscopic colitis causes chronic watery diarrhea, but the colon lining shows little or no signs of inflammation. It may be genetically linked to celiac sprue. Most patients can expect to improve.

Celiac Sprue. Celiac sprue, or celiac disease, is an intolerance to gluten (found in wheat) that triggers inflammation in the small intestine and causes diarrhea, vitamin deficiencies, and stool abnormalities. It occurs in a significant number of people with IBD and is usually first noticed in children.

Click the icon to see foods to avoid when you have celiac sprue.

Interstitial Cystitis. Interstitial cystitis (IC) is an inflammation of the bladder wall that occurs almost exclusively in women. Some evidence suggests that the risk for IBD in these patients is 100 times above that in the general population and that there may be some common factor to both conditions. The average age of patients with IC is 40, but 25% of cases occur in women under 30. Symptoms are very similar to urinary tract infections, but no bacteria are present. Pain during sex is a very common complaint in these patients, and stress may intensify symptoms.

Infections. If endoscopy reveals inflammation, a physician must always rule out possible infections before a diagnosis of inflammatory bowel disease can be confirmed.

Acute Appendicitis. Crohn's disease may cause tenderness in the right lower part of the abdomen where the appendix is located and resembles appendicitis.

Cancer. Colon or rectal cancers must always be ruled out when symptoms of IBD occur.

Intestinal Ischemia. Symptoms similar to IBS can be caused by blockage of blood flow in the intestine. This is more likely to occur in elderly people.