Ulcerative colitis

Ulcerative colitis is an inflammatory bowel disease. Inflammation in the lining of the large intestine (the colon) causes ulcers to form. This can cause bleeding, diarrhea, weight loss, and fatigue.

Ulcerative colitis is an autoimmune disease. That means the immune system, which normally helps fight off infections, mistakenly attacks the lining of the colon and rectum.

Ulcerative colitis almost always involves the rectum. When confined to the rectum, the condition is called ulcerative proctitis. In most people, the inflammation spreads to involve more of the colon, often the entire colon.

Ulcerative colitis can also cause inflammation in other parts of the body. These include the eyes, skin, liver, back, and joints.

The cause of ulcerative colitis is still something of a mystery. The following factors likely play roles:

  • genes. Ulcerative colitis tends to run in families. Up to one in four people with ulcerative colitis has a parent or sibling with ulcerative colitis or with a related inflammatory bowel disease called Crohn's disease.
  • an overactive immune system. The immune system protects the body from infection by identifying and destroying harmful germs. In ulcerative colitis, the immune system does this but also attacks the lining of the large intestine.

Symptoms of ulcerative colitis

Some people with ulcerative colitis have only occasional symptoms. For others, the symptoms are constant. The symptoms a person experiences can vary depending on the severity of the inflammation and where it occurs in the large intestine.

Common symptoms include:

  • diarrhea, often with blood and mucus
  • cramping abdominal pain, especially in the lower abdomen
  • a frequent sensation of needing to have a bowel movement
  • little advance warning before a bowel movement
  • the need to wake from sleep to have bowel movements
  • feeling tired
  • loss of appetite
  • weight loss
  • fever
  • dehydration
  • low red blood cell count (anemia)

Some people with ulcerative colitis develop pain or soreness in the joints, irritated eyes, and rashes.

The symptoms of ulcerative colitis can suddenly get worse. This is called a flare. Then symptoms may fade away. This is called remission. Some individuals with ulcerative colitis have symptoms only rarely, others have flares and remissions, others have symptoms all or most of the time.

Diagnosing ulcerative colitis

There is no single, definitive diagnostic test for ulcerative colitis. If you have this condition, your symptoms and the results of various tests will fit a pattern over time.

Some tests are often, but not always, abnormal in people with Crohn's disease:

  • blood tests can show a lot of white blood cells or other signs of inflammation, or anemia, a reduced number of red blood cells.
  • stool tests, also called feces or bowel movement tests, can detect white blood cells in the stool, a sign of possible ulcerative colitis, and also tell if an infection is causing the symptoms.
  • flexible sigmoidoscopy or colonoscopy lets a doctor look at the insides of the large intestine. This can reveal the presence of ulcers in the large intestine.
  • an x-ray or CT scan may be done to check for serious complications of ulcerative colitis, such as a perforated colon, or to determine how much of the colon is inflamed.

Treating ulcerative colitis

So far, there is no cure for ulcerative colitis. But there are ways to manage this condition to prevent flare-ups or reduce their intensity.

Lifestyle changes

Certain foods can trigger ulcerative colitis symptoms. Different foods affect different people. Common trigger foods include:

  • milk, yogurt, cheese, and other dairy products
  • coffee, tea, soda, and other beverages that contain caffeine
  • alcohol
  • fruit and juice
  • fried, fatty, and spicy foods
  • whole-grain and multigrain breads
  • condiments, such as ketchup, mustard, and mayonnaise
  • salad dressing
  • some vegetables, including cabbage, broccoli, and cauliflower
  • red meat
  • beans and lentils
  • spices and seasonings
  • artificial colors, flavors, and sweeteners

To find out if any foods cause your symptoms to flare up, keep a food diary. Record exactly what you eat over several weeks, along with how you feel afterwards. When you look back, you may notice a pattern. If certain foods worsen your symptoms, talk to your doctor about eliminating them from your diet.

Some people with ulcerative colitis don’t get enough vitamins, minerals, and other important micronutrients, either because they eat less to avoid diarrhea or because the disease makes it difficult to absorb nutrients from food. Eating a well-balanced, nutritious diet can help. It may also be necessary to take a multivitamin, multimineral supplement.

Non-steroidal anti-inflammatory drugs such as aspirin, ibuprofen, and naproxen can trigger or worsen the symptoms of ulcerative colitis. A better choice for pain relief is acetaminophen.


Medications cannot cure ulcerative colitis, but they can stop or ease symptoms. They work by quelling inflammation in the intestine:

  • aminosalicylates. These anti-inflammatory drugs, which are related to aspirin, are used to ease mild to moderate symptoms or to help people stay symptom-free.
  • corticosteroids. These drugs quiet the immune system and decrease inflammation. They can also help stop or ease symptoms. Corticosteroids are usually used when symptoms do not respond to aminosalicylates. Because of potential side effects, they are not usually used long-term.
  • immunomodulators. These medications reduce the activity of the immune system. This reduces inflammation in the colon, which can help keep a person symptom free. Immunomodulators can take up to three months to start working. They are usually needed when aminosalicylates alone do not keep inflammation controlled.
  • biologics. These drugs target a protein made by the immune system. They decrease inflammation in the large intestine and can also quickly stop symptoms.

Other medications that may be needed include:

  • acetaminophen, to relieve pain
  • antibiotics, to prevent or treat bacterial infections in the gastrointestinal tract
  • medication to slow or stop diarrhea
  • medication to decrease spasms of the colon


Surgery to remove the colon and rectum may be an option for people who have:

  • severe symptoms not controlled by medicine
  • unacceptable side effects from medicine
  • a very high risk of colon cancer because of long-lasting inflammation throughout the colon

Surgery involves removing the colon and some or all of the rectum and anus. There are two types of surgery for ulcerative colitis:

The surgeon removes the entire colon and rectum and then creates an opening in the abdominal wall. The end of the small intestine is attached to this opening. After this procedure, waste leaves the body through the opening in the abdominal wall, rather than through the anus. A bag attached to the opening collects the waste.

The surgeon removes the colon and then connects the small intestine to the anus. After this procedure, normal bowel movements still occur.

Ulcerative colitis and colorectal cancer

Ulcerative colitis increases the risk of colorectal cancer. Colorectal cancer often begins as small growths (polyps) on the inside of the large intestine. The risk of colorectal cancer increases based on:

  • the length of time a person has had ulcerative colitis
  • how much of the colon is affected by ulcerative colitis

People with ulcerative colitis should have more frequent tests for polyps and colorectal cancer than people at average risk. The gold standard screening test is a colonoscopy. Polyps can be removed during a colonoscopy. This reduces the risk of colorectal cancer. Ask your doctor how often you should be checked for colorectal cancer.

Surgery to remove the entire colon eliminates the risk of colon cancer.


As a service to our readers, Harvard Health Publishing provides access to our library of archived content. Please note the date of last review or update on all articles.

No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician.

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