Ulcerative colitis is a chronic disease in which abnormal reactions of the immune system cause inflammation and ulcers on the inner lining of your large intestine.
Ulcerative colitis can begin gradually and become worse over time. However, it can also start suddenly. Symptoms can range from mild to severe. In between periods of flares—times when people have symptoms—most people have periods of remission—times when symptoms disappear. Periods of remission can last for weeks or years. The goal of treatment is to keep people in remission long term.
Crohn’s disease and ulcerative colitis affect as many as 1.6 million Americans. Patients with IBD have immune systems that attack their own intestines, resulting in inflammation. Recent years have seen a steady increase in reported cases of IBD in Black Americans.
Although the risk is slightly lower than that of white Americans, Black Americans are at significant risk for IBD.
Ulcerative colitis is an inflammatory bowel disease (IBD). Crohn’s disease and microscopic colitis are other common types of IBD.
Symptoms of ulcerative colitis vary from person to person. Common symptoms of ulcerative colitis include:
Symptoms of ulcerative colitis may vary in severity. For example, mild symptoms may include having fewer than four bowel movements a day and sometimes passing blood with stool. Severe symptoms may include having more than six bowel movements a day and passing blood with stool most of the time. In extremely severe—or fulminant—ulcerative colitis, you may have more than 10 bloody bowel movements in a day.
Some symptoms are more likely to occur if ulcerative colitis is more severe or affects more of the large intestine. These symptoms include:
You may have periods of remission—times when symptoms disappear—that can last for weeks or years. After a period of remission, you may have a relapse, or a return of symptoms.
Doctors aren’t sure what causes ulcerative colitis. Experts think that the following factors may play a role in causing ulcerative colitis.
Ulcerative colitis sometimes runs in families. Research suggests that certain genes increase the chance that a person will develop ulcerative colitis.
Abnormal reactions of the immune system may play a role in causing ulcerative colitis. Abnormal immune reactions lead to inflammation in the large intestine.
The microbes in your digestive tract—including bacteria, viruses, and fungi—that help with digestion are called the microbiome. Studies have found differences between the microbiomes of people who have IBD and those who don’t. Researchers are still studying the relationship between the microbiome and IBD.
Experts think a person’s environment—one’s surroundings and factors outside the body—may play a role in causing ulcerative colitis. Researchers are still studying how people’s environments interact with genes, the immune system, and the microbiome to affect the chance of developing ulcerative colitis.
To diagnose ulcerative colitis, doctors review medical and family history, perform a physical exam, and order medical tests. Doctors order tests to:
During a physical exam, your doctor may:
The physical exam may also include a digital rectal exam to check for blood in your stool.
Doctors may use blood tests, stool tests, and endoscopy of the large intestine to diagnose ulcerative colitis.
A healthcare professional will take a blood sample from you and send the sample to a lab. Doctors use blood tests to check for signs of ulcerative colitis and complications, such as anemia. Blood tests can also show signs of infection or other digestive diseases.
A healthcare professional will give you a container for catching and storing the stool. You will receive instructions on where to send or take the container for analysis. Doctors may use stool tests to check for conditions other than ulcerative colitis, such as infections that could be causing your symptoms. Doctors may also use stool tests to check for signs of inflammation in the intestines.
Doctors order an endoscopy of the large intestine with biopsies to diagnose ulcerative colitis and rule out other digestive conditions. Doctors also use endoscopy to find out how severe ulcerative colitis is and how much of the large intestine is affected.
During an endoscopy, doctors use an endoscope—a long, flexible, narrow tube with a light and a tiny camera on one end—to view the lining of the large intestine. Doctors obtain biopsies by passing an instrument through the endoscope to take small pieces of tissue from the lining of your rectum and colon. A pathologist will examine the tissue under a microscope.
Two types of endoscopy used to diagnose ulcerative colitis are:
To help diagnose ulcerative colitis, your doctor will ask about your symptoms, your medical history, and any medicines you take. Your doctor will also ask about lifestyle factors, such as smoking, and about your family medical history.
Ulcerative colitis is more likely to develop in people:
Ulcerative colitis may lead to complications that develop over time, such as:
In some cases, ulcerative colitis may lead to serious complications that develop quickly and can be life-threatening. These complications require treatment at a hospital or emergency surgery. Serious complications include:
Severe ulcerative colitis or serious complications may lead to additional problems, such as severe anemia and dehydration. These problems may require treatment at a hospital with blood transfusions or intravenous (IV) fluids and electrolytes.
Some people with ulcerative colitis also have inflammation in parts of the body other than the large intestine, including the:
People with ulcerative colitis also have a higher risk of blood clots in their blood vessels.
Ulcerative colitis increases the chance of getting colorectal cancer. People have a higher risk for developing colorectal cancer if ulcerative colitis affects more of their large intestine, is more severe, started at a younger age, or has been present for a longer time. People with ulcerative colitis also have a higher risk of developing colorectal cancer if they have primary sclerosing cholangitis or have a family history of colorectal cancer.
If you have ulcerative colitis, your doctor may recommend a colonoscopy to screen for colorectal cancer. Screening is testing for diseases when you have no symptoms. Screening can check for dysplasia—precancerous cells—or colorectal cancer. Diagnosing cancer early can improve chances for recovery.
For people with ulcerative colitis, doctors typically recommend colonoscopies every 1 to 3 years, starting 8 years after ulcerative colitis started. For people with ulcerative colitis and primary biliary cholangitis, doctors typically recommend colonoscopies every year, starting at diagnosis.
Doctors treat ulcerative colitis with medicines and surgery. Each person experiences ulcerative colitis differently, and doctors recommend treatments based on how severe ulcerative colitis is and how much of the large intestine is affected. Doctors most often treat severe and fulminant ulcerative colitis in a hospital.
Doctors prescribe medicines to reduce inflammation in the large intestine and to help bring on and maintain remission—a time when your symptoms disappear. People with ulcerative colitis typically need lifelong treatment with medicines unless they have surgery to remove the colon and rectum.
Which medicines your doctor prescribes will depend on how severe ulcerative colitis is. Ulcerative colitis medicines that reduce inflammation in the large intestine include:
Your doctor may recommend surgery if you have:
To treat ulcerative colitis, surgeons typically remove the colon and rectum and change how your body stores and passes stool. The most common types of surgery for ulcerative colitis are:
