Ulcerative colitis is an inflammatory bowel disease (IBD) that causes long-lasting inflammation in part of your digestive tract.

Like Crohn’s disease, another common IBD, ulcerative colitis can be debilitating and sometimes can lead to life-threatening complications. Because ulcerative colitis is a chronic condition, symptoms usually develop over time, rather than suddenly.

Ulcerative colitis usually affects only the innermost lining of your large intestine (colon) and rectum. It occurs only through continuous stretches of your colon, unlike Crohn’s disease, which occurs anywhere in the digestive tract and often spreads deeply into the affected tissues.

There’s no known cure for ulcerative colitis, but therapies are available that may dramatically reduce the signs and symptoms of ulcerative colitis and even bring about a long-term remission.

Ulcerative colitis symptoms can vary, depending on the severity of inflammation and where it occurs. For these reasons, doctors often classify ulcerative colitis according to its location.

Here are the signs and symptoms that may accompany ulcerative colitis, depending on its classification:

• Ulcerative proctitis. In this form of ulcerative colitis, inflammation is confined to the area closest to the anus (rectum), and for some people, rectal bleeding may be the only sign of the disease. Others may have rectal pain and a feeling of urgency. This form of ulcerative colitis tends to be the mildest.
• This form involves the rectum and the lower end of the colon, known as the sigmoid colon. Bloody diarrhea, abdominal cramps and pain, and an inability to move the bowels in spite of the urge to do so (tenesmus) are common problems associated with this form of the disease.
• Left-sided colitis. As the name suggests, inflammation extends from the rectum up through the sigmoid and descending colon, which are located in the upper left part of the abdomen. Signs and symptoms include bloody diarrhea, abdominal cramping and pain on the left side, and unintended weight loss.
• Affecting more than the left colon and often the entire colon, pancolitis causes bouts of bloody diarrhea that may be severe, abdominal cramps and pain, fatigue, and significant weight loss.
• Fulminant colitis. This rare, life-threatening form of colitis affects the entire colon and causes severe pain, profuse diarrhea and, sometimes, dehydration and shock. People with fulminant colitis are at risk of serious complications, including colon rupture and toxic megacolon, a condition that causes the colon to rapidly expand.

The course of ulcerative colitis varies, with periods of acute illness often alternating with periods of remission. But over time, the severity of the disease usually remains the same. Most people with a milder condition, such as ulcerative proctitis, won’t go on to develop more-severe signs and symptoms.

Like Crohn’s disease, ulcerative colitis causes inflammation and ulcers in your intestine. But unlike Crohn’s, which can affect the colon in various, separate sections, ulcerative colitis usually affects one continuous section of the inner lining of the colon beginning with the rectum.

No one is quite sure what triggers ulcerative colitis, but there’s a consensus as to what doesn’t. Researchers no longer believe that stress is the main cause, although stress can often aggravate symptoms. Instead, current thinking focuses on the following possibilities:

• Immune system. Some scientists think a virus or bacterium may trigger ulcerative colitis. The digestive tract becomes inflamed when your immune system tries to fight off the invading microorganism (pathogen). It’s also possible that inflammation may stem from an autoimmune reaction in which your body mounts an immune response even though no pathogen is present.
• Because you’re more likely to develop ulcerative colitis if you have a parent or sibling with the disease, scientists suspect that genetic makeup may play a contributing role. However, most people who have ulcerative colitis don’t have a family history of this disorder.

Ulcerative colitis affects about the same number of women and men. Risk factors may include:

• Ulcerative colitis usually begins before the age of 30. But, it can occur at any age, and some people may not develop the disease until their 50s or 60s.
• Family history. You’re at higher risk if you have a close relative, such as a parent, sibling or child, with the disease.

Possible complications of ulcerative colitis include:

• Severe bleeding
• A hole in the colon (perforated colon)
• Severe dehydration
• Liver disease (rare)
• Kidney stones
• Osteoporosis
• Inflammation of your skin, joints and eyes
• An increased risk of colon cancer
• A rapidly swelling colon (toxic megacolon)

We diagnose ulcerative colitis only after ruling out other possible causes for your signs and symptoms, including Crohn’s disease, ischemic colitis, infection, irritable bowel syndrome (IBS), diverticulitis and colon cancer. To help confirm a diagnosis of ulcerative colitis, you may have one or more of the following tests and procedures:

• Blood tests
• Stool sample
• This exam allows your doctor to view your entire colon using a thin, flexible, lighted tube with an attached camera. During the procedure, your doctor can also take small samples of tissue (biopsy) for laboratory analysis. Sometimes a tissue sample can help confirm a diagnosis.
• CT scan. A CT scan of your abdomen or pelvis may be performed if your doctor suspects a complication from ulcerative colitis or inflammation of the small intestine that might suggest Crohn’s disease. A CT scan may also reveal how much of the colon is inflamed.

The goal of medical treatment is to reduce the inflammation that triggers your signs and symptoms. In the best cases, this may lead not only to symptom relief but also to long-term remission. Ulcerative colitis treatment usually involves either drug therapy or surgery.

Doctors use several categories of drugs that control inflammation in different ways. But drugs that work well for some people may not work for others, so it may take time to find a medication that helps you. In addition, because some drugs have serious side effects, you’ll need to weigh the benefits and risks of any treatment.

Anti-inflammatory drugs are often the first step in the treatment of inflammatory bowel disease. They include:

• Sulfasalazine
• Corticosteroids aren’t for long-term use, and the dose is usually tapered down over two to three months.

They may also be used in conjunction with other medications as a means to induce remission. For example, corticosteroids may be used with an immune system suppressor — the corticosteroids can induce remission, while the immune system suppressors can help maintain remission. Occasionally, we may also prescribe short-term use of steroid enemas to treat disease in your lower colon or rectum.

These drugs also reduce inflammation, but they target your immune system rather than treating inflammation itself. By suppressing this response, inflammation is also reduced. Immunosuppressant drugs include:

• Azathioprine
• Cyclosporine
• Infliximab
• Adalimumab

If diet and lifestyle changes, drug therapy, or other treatments don’t relieve your signs and symptoms, we may recommend surgery.

Surgery can often eliminate ulcerative colitis. But that usually means removing your entire colon and rectum (proctocolectomy). In the past, after this surgery you would wear a small bag over an opening in your abdomen (ileal stoma) to collect stool. But a procedure called ileoanal anastomosis eliminates the need to wear a bag. Instead, your surgeon constructs a pouch from the end of your small intestine. The pouch is then attached directly to your anus. This allows you to expel waste more normally, although you may have more-frequent bowel movements that are soft or watery because you no longer have your colon to absorb water.

Screening for colon cancer often needs to be done more frequently because people who have ulcerative colitis have an increased risk of colon cancer. It’s recommended that people with pancolitis begin colon cancer screening with a colonoscopy eight years after diagnosis. For those who have left-sided colitis, screening with colonoscopy is recommended beginning 10 years after diagnosis. People with proctitis can follow the usual colon cancer screening guidelines that call for a colonoscopy every 10 years beginning at age 50.

There’s no firm evidence that what you eat causes inflammatory bowel disease. But certain foods and beverages can aggravate your symptoms, especially during a flare-up in your condition. It’s a good idea to try eliminating from your diet anything that seems to make your signs and symptoms worse. Here are some suggestions that may help:

• Limit dairy products
• Experiment with fiber.
• Avoid problem foods.
• Eat small meals.
• Drink plenty of liquids.
• Multivitamins

Although stress doesn’t cause inflammatory bowel disease, it can make your signs and symptoms much worse and may trigger flare-ups.

When you’re stressed, your normal digestive process can change, causing your stomach to empty more slowly and secrete more acids. Stress can also speed or slow the passage of intestinal contents. It may also cause changes in intestinal tissue itself.

Although it’s not always possible to avoid stress, you can learn ways to help manage it. Some of these include:

• Exercise
• Regular relaxation and breathing exercises.