Ulcerative colitis is a chronic (ongoing) disease of the colon, or large intestine. The disease is marked by inflammation and ulceration of the colon mucosa, or innermost lining.
Tiny open sores, or ulcers, form on the surface of the lining, where they bleed and produce pus and mucus. Because the inflammation makes the colon empty frequently, symptoms typically include diarrhea (sometimes bloody) and often crampy abdominal pain.
The inflammation usually begins in the rectum and lower colon, but it may also involve the entire colon. When ulcerative colitis affects only the lowest part of the colon - the rectum - it is called ulcerative proctitis. If the disease affects only the left side of the colon, it is called limited or distal colitis. If it involves the entire colon, it is termed pancolitis.
Ulcerative colitis differs from another inflammatory bowel disease (IBD), Crohn's disease. Crohn's can affect any area of the gastrointestinal (GI) tract, including the small intestine and colon. Ulcerative colitis, on the other hand, affects only the colon. The inflammation involves the entire rectum and extends up the colon in a continuous manner.
There are no areas of normal intestine between the areas of diseased intestine. In contrast, such so-called "skip" areas may occur in Crohn's disease. Ulcerative colitis affects only the innermost lining of the colon, whereas Crohn's disease can affect the entire thickness of the bowel wall.
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.
Neither ulcerative colitis nor Crohn's disease should be confused with irritable bowel syndrome (IBS), a disorder that affects the motility (muscle contractions) of the colon. Sometimes called "spastic colon" or "nervous colitis", IBS is not characterized by intestinal inflammation. It is, therefore, a much less serious disease than ulcerative colitis. IBS bears no direct relationship to either ulcerative colitis or Crohn's disease.
The first symptom of ulcerative colitis is a progressive loosening of the stool. The stool is generally bloody and may be associated with crampy abdominal pain and severe urgency to have a bowel movement. The diarrhea may begin slowly or quite suddenly. Loss of appetite and subsequent weight loss are common, as is fatigue. In cases of severe bleeding, anemia may also occur. In addition, there may be skin lesions, joint pain, eye inflammation and liver disorders. Children with ulcerative colitis may fail to develop or grow properly.
Approximately half of all patients with ulcerative colitis have relatively mild symptoms. However, others may suffer from severe abdominal cramping, bloody diarrhea, nausea, and fever. The symptoms of ulcerative colitis do tend to come and go, with fairly long periods in between flare-ups in which patients may experience no distress at all.
These periods of remission can span months or even years, although symptoms do eventually return. The unpredictable course of ulcerative colitis may make it difficult for physicians to evaluate whether a particular course of treatment has been effective or not.
Types of Ulcerative Colitis and Their Associated Symptoms
The symptoms of ulcerative colitis, as well as possible complications, will vary depending on the extent of inflammation in the rectum and the colon. Because of this, it is very important for you to know which part of your intestine the disease affects.
One common subcategory of ulcerative colitis is ulcerative proctitis. For approximately 30% of all patients with ulcerative colitis, the illness begins as ulcerative proctitis. In this form of the disease, bowel inflammation is limited to the rectum. Because of its limited extent (usually less than the six inches of the rectum), ulcerative proctitis tends to be a milder form of ulcerative colitis. It is associated with fewer complications and offers a better outlook than more widespread disease.
In addition to ulcerative proctitis, there are several other types of ulcerative colitis. The following is a description of each type, together with some commonly associated symptoms and potential intestinal complications:
Proctosigmoiditis: Colitis affecting the rectum and the sigmoid colon (the lower segment of colon located right above the rectum). Symptoms include bloody diarrhea, cramps, and tenesmus. Moderate pain on the lower left side of the abdomen may occur in active disease.
- Left-sided colitis: Continuous inflammation that begins at the rectum and extends as far as the splenic flexure (a bend in the colon, near the spleen). Symptoms include loss of appetite, weight loss, diarrhea, severe pain on the left side of the abdomen, and bleeding.
- Pan-ulcerative (total) colitis: Affects the entire colon. Symptoms include diarrhea, severe abdominal pain, cramps, and extensive weight loss. Potentially serious complications include massive bleeding and acute dilation of the colon (toxic megacolon), which may lead to perforation (an opening in the bowel wall). Serious complications may require surgery.
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 person 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.
Many scientists now believe that the interaction of an outside agent (such as a virus or bacterium) with the body's immune system may trigger the disease, or that such an agent may cause damage to the intestinal wall, initiating or accelerating the disease process.
Currently, there is no medical cure for ulcerative colitis. However, effective medical treatment can suppress the inflammatory process. This accomplishes two important goals: It permits the colon to heal and it also relieves the symptoms of diarrhea, rectal bleeding, and abdominal pain. As such, the treatment of ulcerative colitis involves medications that decrease the abnormal inflammation in the colon lining and thereby control the symptoms.
Five major classes of medication are used today to treat ulcerative colitis:
Aminosalicylates (5-ASA). These medications typically are used to treat mild to moderate symptoms. Without inflammation, symptoms such as diarrhea, rectal bleeding, and abdominal pain can be diminished greatly. Aminosalicylates are effective in treating mild to moderate episodes of ulcerative colitis, and are also useful in preventing relapses of this disease.
Corticosteroids nonspecifically suppress the immune system and are used to treat moderate to severely active ulcerative colitis (by "nonspecifically," we mean that these drugs do not target specific parts of the immune system that play a role in inflammation, but rather, that they suppress the entire immune response).
These drugs have significant short- and long-term side effects and should not be used as a maintenance medication. If you cannot come off steroids without suffering a relapse of your symptoms, your doctor may need to add some other medications to help manage your disease.
Immune modifiers, sometimes called immunomodulators, are used to help decrease corticosteroid dosage . They also may be helpful in maintaining remission in selected refractory ulcerative colitis patients (that is, patients who do not respond to standard medications). However, these medications can take as long as three months before their beneficial effects begin to work.
Antibiotics: metronidazole, ampicillin, ciprofloxacin, others.
Biologic therapies are the newest class of drugs used for people suffering from moderate-to-severe ulcerative colitis. These drugs are made from antibodies that bind with certain molecules to block a particular action. The intestinal inflammation of ulcerative colitis is a result of various processes, or "pathways." Because a biologic drug targets a specific pathway, it can help reduce inflammation. That targeted action also keeps side effects to a minimum.