What is ulcerative colitis? A Mayo Clinic expert explains

Listen to gastroenterologist William Faubion, M.D., walk through ulcerative colitis basics.

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William A. Faubion, Jr., M.D., Gastroenterology, Mayo Clinic I'm Dr. Bill Faubion, a gastroenterologist at Mayo Clinic. In this video, we'll cover the basics of ulcerative colitis. What is it? Who gets it? The symptoms, diagnosis, and treatment. Whether you're looking for answers for yourself or someone you love, we're here to give you the best information available.

Ulcerative colitis is an inflammatory bowel disease that causes chronic inflammation and ulcers in the superficial lining of the large intestine, also called the colon. And that includes the rectum. It's estimated that about a million Americans are living with ulcerative colitis, making it the most common form of inflammatory bowel disease. It can be painful and debilitating, occasionally leading to severe complications. It can also be emotionally stressful. And while there is no cure, once you've been diagnosed, treatment can help you get back to a much more normal and comfortable life.

Who gets it?

The exact cause of ulcerative colitis is unknown, but there are things that appear to trigger or aggravate it. It may involve an abnormal immune response against some microorganism in which your tissues are also attacked. Genetics might also play a role. You are at higher risk if a first-degree relative has it. There's also a correlation with age. Although it can show up at any stage of life, most people are diagnosed before the age of 30. And ethnicity is a risk factor. Whites have the highest risk, especially among people of Ashkenazi Jewish descent. While diet and stress don't cause ulcerative colitis, they are known to exacerbate symptoms.

What are the symptoms?

Most people have mild to moderate cases of ulcerative colitis. Although it can be more severe, you may also experience periods of remission when you have no issues at all. A person's symptoms depend on the severity of the case in the area of the colon that's involved. They usually develop over time, and they can include diarrhea, often with blood or pus, fever, fatigue, anemia, loss of appetite and weight loss, abdominal pain and cramping, rectal pain and bleeding, the need for a bowel movement, yet the inability to do so despite the urgency. And in children, delayed growth and development. Over time, ulcerative colitis can lead to other complications, such as severe dehydration, a perforated colon, bone loss, inflammation of your skin, joints and eyes. It can also increase your risk for blood clots and colon cancer. These symptoms don't automatically mean that you have ulcerative colitis. But if you're experiencing anything that concerns you, it's a good idea to make an appointment with your doctor.

How is it diagnosed?

The only way to definitively diagnose ulcerative colitis is with a biopsy after taking a tissue sample through an endoscopic procedure. But first, less invasive things can be done to rule out other causes. First, your doctor will consider your medical history. They may want to run a variety of tests or procedures. And at some point, your general practitioner may refer you to a specialist called a gastroenterologist like myself. A blood test can check for anemia and check for signs of infection. A stool study can test for white blood cells and other specific proteins that point to ulcerative colitis, as well as rule out certain pathogens. A colonoscopy may be needed. This allows your doctor to view the entirety of the large intestine using an endoscope, a small camera mounted on a thin flexible tube. They can take tissue samples for a biopsy at the same time. Or if your colon is extremely inflamed, they may do a flexible sigmoidoscopy, which only goes as far as the rectum and lower or sigmoid colon. If your symptoms are more severe, your doctor may want some imaging done. An abdominal x-ray can rule out serious complications, like a perforated colon. An MRI or CT scan can also be performed for a more detailed view of the bowel, as well as to reveal the extent of the inflammation.

How is it treated?

Although there is no cure for ulcerative colitis there are widely effective treatments, usually involving either drug therapy or surgery. Your doctor can work with you to find things that alleviate your symptoms and in some cases, even bring about long-term remission. Treatments may include anti-inflammatory drugs like corticosteroids and immune system suppressants. Certain targeted therapies directed against the immune system called biologics can help. Antidiarrheals, pain relievers, antispasmodics and iron supplements can help counter other symptoms. And surgery may be required to remove the damaged tissue. In extreme cases, the whole colon may be removed. Which sounds drastic, but this can sometimes be the best option for eliminating the pain and struggle of ulcerative colitis once and for all. Some of these therapies may have side effects themselves. So be sure to review the risks and benefits with your doctor.

What now?

Ulcerative colitis can be physically and emotionally challenging, but there are things that can help. Although there's no firm evidence that any foods cause ulcerative colitis, certain things seem to aggravate flare-ups. So a food diary can help you identify personal triggers. Beyond that, limit dairy products, eat small meals, stay hydrated, try to avoid caffeine and alcohol and carbonation. If you're concerned about weight loss or if your diet has become too limited, talk to a registered dietitian. It's important to take care of your mental health, too. Find ways to manage stress, like exercise, breathing and relaxation techniques or biofeedback. Some symptoms like abdominal pain, gas, and diarrhea can cause anxiety and frustration. That can make it difficult to be out in public for any amount of time. It can feel limiting and isolating and lead to depression. So learn as much as you can about ulcerative colitis. Staying informed can help a lot in feeling like you're in control of your condition. Talk to a therapist, especially one familiar with inflammatory bowel disease. Your doctor should be able to give you some recommendations. And you might want to find a support group for people going through the same thing that you are. Ulcerative colitis is a complex disease, but having expert medical care and developing a treatment strategy can make it more manageable and even help patients get back to the freedom of a normal life. Meanwhile, significant advances continue to be made in understanding and treating the disease and getting us closer to curing it or preventing it entirely. If you'd like to learn even more about ulcerative colitis, watch our other related videos or visit mayoclinic.org. We wish you well.

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Ulcerative colitis (UL-sur-uh-tiv koe-LIE-tis) is an inflammatory bowel disease (IBD) that causes inflammation and ulcers (sores) in your digestive tract. Ulcerative colitis affects the innermost lining of your large intestine, also called the colon, and rectum. In most people, symptoms usually develop over time, rather than suddenly.

Ulcerative colitis can be draining and can sometimes lead to life-threatening complications. While it has no known cure, there are several new treatments that can greatly reduce signs and symptoms of the disease and bring about long-term remission.


Ulcerative colitis symptoms can vary, depending on the severity of inflammation and where it occurs. Signs and symptoms may include:

  • Diarrhea, often with blood or pus
  • Rectal bleeding — passing small amount of blood with stool
  • Abdominal pain and cramping
  • Rectal pain
  • Urgency to defecate
  • Inability to defecate despite urgency
  • Weight loss
  • Fatigue
  • Fever
  • In children, failure to grow

Most people with ulcerative colitis have mild to moderate symptoms. The course of ulcerative colitis may vary, with some people having long periods when it goes away. This is called remission.


Health care providers often classify ulcerative colitis according to its location. Symptoms of each type often overlap. Types of ulcerative colitis include:

  • Ulcerative proctitis. Inflammation is confined to the area closest to the anus, also called the rectum. Rectal bleeding may be the only sign of the disease.
  • Proctosigmoiditis. Inflammation involves the rectum and sigmoid colon — the lower end of the colon. Symptoms include bloody diarrhea, abdominal cramps and pain, and an inability to move the bowels despite the urge to do so. This is called tenesmus.
  • Left-sided colitis. Inflammation extends from the rectum up through the sigmoid and descending portions of the colon. Symptoms include bloody diarrhea, abdominal cramping and pain on the left side, and urgency to defecate.
  • Pancolitis. This type often affects the entire colon and causes bouts of bloody diarrhea that may be severe, abdominal cramps and pain, fatigue, and significant weight loss.

When to see a doctor

See your health care provider if you experience a persistent change in your bowel habits or if you have signs and symptoms such as:

  • Abdominal pain
  • Blood in your stool
  • Ongoing diarrhea that doesn't respond to nonprescription medications
  • Diarrhea that awakens you from sleep
  • An unexplained fever lasting more than a day or two

Although ulcerative colitis usually isn't fatal, it's a serious disease. In some cases, ulcerative colitis may cause life-threatening complications.

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The exact cause of ulcerative colitis remains unknown. Previously, diet and stress were suspected. However, researchers now know that these factors may aggravate but don't cause ulcerative colitis.

One possible cause is an immune system malfunction. When your immune system tries to fight off an invading virus or bacterium, an irregular immune response causes the immune system to attack the cells in the digestive tract, too.

Heredity also seems to play a role in that ulcerative colitis is more common in people who have family members with the disease. However, most people with ulcerative colitis don't have this family history.

Risk factors

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

  • Age. Ulcerative colitis usually begins before the age of 30, but it can occur at any age. Some people may not develop the disease until after age 60.
  • Race or ethnicity. Although white people have the highest risk of the disease, it can occur in any race. If you're of Ashkenazi Jewish descent, your risk is even higher.
  • 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
  • Severe dehydration
  • A rapidly swelling colon, also called a toxic megacolon
  • A hole in the colon, also called a perforated colon
  • Increased risk of blood clots in veins and arteries
  • Inflammation of the skin, joints and eyes
  • An increased risk of colon cancer
  • Bone loss, also called osteoporosis

Sept. 16, 2022
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