Ulcerative colitis is a chronic disease in which the large intestine becomes inflamed and ulcerated (pitted or eroded), leading to flare-ups (bouts or attacks) of bloody diarrhea, abdominal cramps, and fever. The long-term risk of colon cancer is increased.
Ulcerative colitis may start at any age but usually begins between the ages of 15 and 30. A small group of people have their first attack between the ages of 50 and 70.
Ulcerative colitis usually does not affect the full thickness of the wall of the large intestine and hardly ever affects the small intestine. The disease usually begins in the rectum or the rectum and the sigmoid colon (the lower end of the large intestine) but may eventually spread along part or all of the large intestine.
Ulcerative proctitis, which is confined to the rectum, is a very common and relatively benign form of ulcerative colitis. In some people, most of the large intestine is affected early on.
The cause of ulcerative colitis is not known for certain, but heredity and an overactive immune response in the intestine seem to be contributing factors. Cigarette smoking, which is detrimental in Crohn's disease, seems to decrease the risk of ulcerative colitis. However, smoking in order to reduce the risk of ulcerative colitis is ill-advised in light of the many health problems that smoking can cause.
The symptoms of ulcerative colitis occur in flare-ups. A flare-up may be sudden and severe, causing violent diarrhea (typically bloody), high fever, abdominal pain, and peritonitis (inflammation of the lining of the abdominal cavity). During such flare-ups, the person is profoundly ill. More often, a flare-up begins gradually, and the person has an urgency to have a bowel movement (defecate), mild cramps in the lower abdomen, and visible blood and mucus in the stool. A flare-up can last days or weeks and can recur at any time.
When the disease is limited to the rectum and the sigmoid colon, the stool may be normal or hard and dry; however, mucus containing large numbers of red and white blood cells is discharged from the rectum during or between bowel movements. General symptoms of illness, such as fever, are mild or absent.
If the disease extends farther up the large intestine, the stool is looser, and the person may have as many as 10 to 20 bowel movements a day. Often, the person has severe abdominal cramps and distressing, painful spasms that accompany the urge to defecate. There is no relief at night. The stool may be watery and contain pus, blood, and mucus. Frequently, the stool consists almost entirely of blood and pus. The person also may have a fever and a poor appetite and may lose weight.
Bleeding, the most common complication, often causes iron deficiency anemia. In nearly 10% of people with ulcerative colitis, a rapidly progressive first attack becomes very severe, with massive bleeding, perforation, or widespread infection.
Toxic colitis, a particularly severe complication, involves damage to the entire thickness of the intestinal wall. The damage causes ileus—a condition in which the normal contractile movements of the intestinal wall temporarily stop—so that the intestinal contents are not propelled along their way. Abdominal expansion (distention) develops. As toxic colitis worsens, the large intestine loses muscle tone, and within days—or even hours—it starts to dilate. X-rays of the abdomen show gas inside the paralyzed sections of intestine.
Toxic megacolon occurs when the large intestine greatly expands (distends). The person is severely ill and may have a high fever. The person also has pain and tenderness in the abdomen and a high white blood cell count. If the intestine ruptures, the risk of death is great. However, of the people who receive prompt treatment before rupture occurs, fewer than 2% die.
Colon cancer occurs in as many as 1 of 100 to 200 people with ulcerative colitis each year in the later stages of their illness. The risk of colon cancer is highest when the entire large intestine is affected and the person has had ulcerative colitis for more than 8 years, even if the disease has not always been clinically active. Colonoscopy (examination of the large intestine using a flexible viewing tube) every 1 to 2 years is advised for people who have had ulcerative colitis for at least 8 years. During colonoscopy, tissue samples (biopsies) are obtained from areas throughout the large intestine for microscopic examination to detect the early warning signs of cancer (dysplasia). Most people survive if the diagnosis of dyplasia or even cancer is made during the early stages and the colon is removed in time.
Other complications can occur, as in Crohn's disease. When ulcerative colitis causes a flare-up of gastrointestinal symptoms, the person also may experience inflammation of the joints (arthritis), inflammation of the whites of the eyes (episcleritis), inflamed skin nodules (erythema nodosum), and blue-red skin sores containing pus (pyoderma gangrenosum). When ulcerative colitis is not causing a flare-up of gastrointestinal symptoms, the person still may experience pyoderma gangrenosum, and inflammation of the spine (ankylosing spondylitis), inflammation of the pelvic joints (sacroiliitis), and inflammation of the inside of the eye (uveitis) are liable to occur entirely without relation to the bowel disease. Rarely, blood clots develop in the veins.
Although people with ulcerative colitis commonly have minor liver dysfunction, only about 1 to 3% have symptoms of mild to severe liver disease. Severe liver disease can include inflammation of the liver (chronic active hepatitis); inflammation of the bile ducts (primary sclerosing cholangitis), which narrow and eventually close; and replacement of functional liver tissue with scar tissue (cirrhosis). Inflammation of the bile ducts may appear many years before any intestinal symptoms of ulcerative colitis. The inflammation greatly increases the risk of cancer of the bile ducts and also seems to be associated with a sharp increase in the risk of colon cancer.
The person's symptoms and a stool examination help the doctor suspect the diagnosis. A sigmoidoscopy (an examination of the sigmoid colon using a flexible viewing tube) confirms the diagnosis and permits a doctor to directly observe the severity of the inflammation. Even during symptom-free intervals, the intestine rarely appears entirely normal, and tissue samples removed for microscopic examination usually show chronic inflammation. Blood tests do not confirm the diagnosis but may reveal that the person has anemia, increased numbers of white blood cells, a low level of the protein albumin, and an elevated erythrocyte sedimentation rate (ESR), which indicates active inflammation.
X-rays of the abdomen may indicate the severity and extent of the disease. Barium enema x-ray studies and colonoscopy are not usually done during the active stages of the disease. At some point, however, the entire large intestine is usually evaluated by colonoscopy to determine the extent of the disease.
Prognosis and Treatment
Ulcerative colitis is usually chronic, with repeated flare-ups and remissions. A rapidly progressive initial attack results in serious complications in about 10% of people. Complete recovery after a single attack may occur in another 10%. However, some people who have only a single attack may actually have had an acute undetected infection rather than true ulcerative colitis. Biopsies of the colon can be helpful in making this distinction.
People who have ulcerative proctitis have the best prognosis. Severe complications are unlikely; however, in about 10 to 30% of people, the disease eventually spreads to the large intestine (thus evolving into ulcerative colitis).
Treatment aims to control the inflammation, reduce symptoms, and replace any lost fluids and nutrients.
Iron supplements may offset anemia caused by ongoing blood loss in the stool. Raw fruits and vegetables should be avoided to reduce injury to the inflamed lining of the large intestine. A diet free of dairy products may decrease symptoms and is worth trying but need not be continued if no benefit is noted.
Drugs with anticholinergic effects (such as many antihistamines and some antidepressants) or small doses of loperamide or diphenoxylate are taken for relatively mild diarrhea. For more intense diarrhea, higher doses of diphenoxylate or deodorized opium tincture, loperamide, or codeine may be needed. In severe cases, however, a doctor must closely monitor the person taking these antidiarrheal drugs to avoid precipitating toxic megacolon.
Drugs such as sulfasalazine, olsalazine, mesalamine, and balsalazide are used to reduce the inflammation of ulcerative colitis and to prevent flare-ups of symptoms. These drugs usually are taken by mouth (orally), but mesalamine can also be given as an enema or a suppository (rectally). Whether given orally or rectally, these drugs are at best moderately effective for treating mild or moderately active disease, but they are more effective for maintaining remission and possibly even reducing the long-term risk of colorectal cancer.
People with moderately severe disease who are not confined to bed usually take oral corticosteroids such as prednisone. Prednisone in fairly high doses frequently induces a dramatic remission. After prednisone controls the inflammation of ulcerative colitis, sulfasalazine, olsalazine, or mesalamine often is given to maintain the improvement. Gradually, the prednisone dosage is decreased, and ultimately, the prednisone is discontinued. Prolonged corticosteroid treatment almost always causes side effects. When mild or moderate ulcerative colitis is limited to the left side of the large intestine (descending colon) and the rectum, enemas or suppositories with a corticosteroid or mesalamine may be helpful.
If the disease becomes severe, the person is hospitalized, and corticosteroids and fluids are given intravenously. People with heavy rectal bleeding may require blood transfusions.
Drugs such as azathioprine and mercaptopurine have been used to maintain remissions in people with ulcerative colitis who would otherwise need long-term corticosteroid therapy. These drugs inhibit the function of T cells, which are an important component of the immune system. However, these drugs are slow to act, and a benefit may not be seen for 1 to 4 months. They also have potentially serious side effects that require close monitoring by the doctor.
Cyclosporine has been given to some people who have severe flare-ups and have not responded to corticosteroid therapy. Most of these people respond initially to the cyclosporine, but some may still ultimately require surgery.
Infliximab, which is derived from monoclonal antibodies and given intravenously, is beneficial for some people with ulcerative colitis. This drug may be given to people who do not respond to corticosteroids or who develop symptoms whenever corticosteroid doses are lowered, despite the optimal use of other immunomodulating drugs.
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About 30% of people with extensive ulcerative colitis require surgery. Emergency surgery may be necessary for acute life-threatening attacks with massive bleeding, perforations, toxic megacolon, or blood clotting. Nonemergency reasons for surgery include unremitting chronic disease that is disabling or that constantly requires high doses of corticosteroids.
Surgery is also performed on a nonemergency basis when cancer is diagnosed or dysplasia is identified in the large intestine, and sometimes when there is narrowing of the large intestine or growth retardation in children.
Complete removal of the large intestine and rectum permanently cures ulcerative colitis. Living with a permanent ileostomy (a surgically created connection between the lowest portion of the small intestine and an opening in the abdominal wall) and an ileostomy bag used to be the traditional price of this cure. However, various alternative procedures are now available, the most common one being a procedure called ileo-anal anastomosis. In this procedure, the large intestine and most of the rectum are removed, and a small reservoir is created out of the small intestine and attached to the remaining rectum just above the anus. This procedure maintains continence, although some complications, such as inflammation of the reservoir (pouchitis), may occur.
For people with ulcerative proctitis, surgery is rarely needed, and life expectancy is normal. In some people, though, the symptoms may prove exceptionally resistant to treatment.
Toxic megacolon is an emergency that may require surgery. As soon as a doctor detects it or suspects impending toxic megacolon, all antidiarrheal drugs are discontinued; the person is given nothing to eat; a tube is inserted through the nose and into the stomach or small intestine and attached to intermittent suction; and all fluids, nutrition, and drugs are given intravenously. The person is monitored closely for signs of peritonitis or a perforation. If time and the person's condition permit, drug therapy with cyclosporine or infliximab is sometimes given. If these measures are inappropriate or ineffective, however, emergency surgery is needed: All or most of the large intestine is removed.
Last full review/revision August 2006 by David B. Sachar, MD; Aaron E. Walfish, MD