What is ulcerative colitis?

Ulcerative colitis is a lifelong condition that you have to manage, rather than a life-threatening illness. Still, it’s a serious disease that can cause some dangerous complications, especially if you don’t get the right treatment.

Ulcerative colitis is one form of inflammatory bowel disease (IBD). Crohn’s disease is the other type of IBD. Ulcerative colitis causes inflammation in the inner lining of your rectum and your large intestine, also known as your colon.

It happens when your immune system mistakenly attacks your intestines. The immune system attack causes inflammation and sores or ulcers in your intestines.

Ulcerative colitis is treatable. Most people with this condition can have a full life expectancy. However, complications can increase the risk of an early death, according to one 2003 Danish study.

Very severe ulcerative colitis could impact your life expectancy, especially within the first couple of years after your diagnosis.

While ulcerative colitis itself usually isn’t fatal, some of its complications can be.

Possible complications from ulcerative colitis include:

The most serious complication is toxic megacolon. This is swelling of the colon that can cause it to rupture. It affects up to 10 percent of people with ulcerative colitis.

Death rates from toxic megacolon range from 19 percent to 45 percent. The risk of death is higher if the intestine ruptures and it isn’t treated right away.

A hole in the bowel is also dangerous. Bacteria from your intestine can get into your abdomen and cause a life-threatening infection called peritonitis.

Primary sclerosing cholangitis is another rare but serious complication. It causes swelling and damage to your bile ducts. These ducts carry digestive fluid from your liver to your intestines.

Scars form and narrow the bile ducts, which can eventually cause severe liver damage. In time, you can develop serious infections and liver failure. These problems can be life threatening.

Colorectal cancer is also a serious complication. Between 5 and 8 percent of people with ulcerative colitis develop colorectal cancer within 20 years of their ulcerative colitis diagnosis.

This is slightly higher than the risk of colorectal cancer among people without ulcerative colitis, which is between 3 and 6 percent. Colorectal cancer can be fatal if it spreads to other parts of your body.

Ulcerative colitis can differ from person to person, but it’s usually a lifelong condition. Symptoms come and go over time.

You’ll have flare-ups of symptoms, followed by symptom-free periods called remissions. Some people go years without any symptoms. Others experience flare-ups more often.

Overall, about half of people with ulcerative colitis will have relapses, even if they’re being treated.

You’ll have the best outlook if the inflammation is only in a small area of your colon. Ulcerative colitis that spreads can be more severe and harder to treat.

The one way to cure ulcerative colitis is with surgery to remove your colon and rectum. This is called proctocolectomy. Once your colon and rectum are removed, you’ll also be at lower risk for complications like colon cancer.

You can improve your own outlook by taking good care of your ulcerative colitis and getting regular checkups to look for complications. Once you’ve had ulcerative colitis for about eight years, you’ll also need to start having regular colonoscopies for colon cancer surveillance.

It can be helpful to talk to others who understand what you’re going through. IBD Healthline is a free app that connects you with others living with ulcerative colitis through one-on-one messaging and live group chats, while also providing access to expert-approved information on managing the condition. Download the app for iPhone or Android.

Read this article in Spanish.


  • Take the medicines your doctor has prescribed to manage your condition.
  • Have surgery if you need it.
  • Ask your doctor what screening tests you should get.
Was this helpful?