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Quick Facts

Ulcerative Colitis


The Manual's Editorial Staff

Last full review/revision Jan 2020| Content last modified Jan 2020
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Your digestive tract is the path that food takes through your body after you eat it. Food goes from your mouth (eating) to your anus (passing stool). Your intestine is the long tube in your digestive system that connects your stomach to your anus. It digests food and absorbs nutrients.

You have a small intestine and a large intestine. The small intestine, or small bowel, is very long with many coils. The large intestine, also called the colon or large bowel, is shorter and wider.

What is ulcerative colitis?

Ulcerative colitis is a long-term disease that causes your large intestine (colon) to become inflamed. It doesn't affect your small intestine. Intestines are also called "bowels," so ulcerative colitis is one of two inflammatory bowel diseases. The other inflammatory bowel disease is Crohn disease.

  • Ulcerative colitis is an inflammatory bowel disease

  • Symptoms come and go and include belly cramps, a frequent urge to pass stool, and bloody diarrhea

  • Doctors will look at your stool and use a viewing tube to look at your intestine

  • Doctors use treatments to control inflammation in your intestine, ease symptoms, and replace lost fluids and nutrients

  • Having ulcerative colitis for a long time increases your risk of getting colon cancer

Ulcerative colitis may start at any age but usually begins before age 30.

What causes ulcerative colitis?

Doctors don't know what causes ulcerative colitis. It may be due to a problem with your immune system that causes your intestine to overreact and become inflamed. Ulcerative colitis may run in families and is more common in Jewish people whose families come from Eastern Europe.

What are the symptoms of ulcerative colitis?

Symptoms of ulcerative colitis come and go. A flare-up can be severe for a few days or weeks and then go away or at least get better for a while. For most people, symptoms continue to flare up on and off throughout their life.

Usually, a flare-up begins slowly. Symptoms include:

  • A strong urge to pass stool

  • Mild cramps in your lower belly

  • Blood and mucus in your stool

A flare-up may be sudden and severe, causing:

  • Violent diarrhea often with a lot of mucus and blood

  • Heavy bleeding from your anus

  • High fever

  • Belly pain

Sometimes in a severe flare up, your large intestine swells up a lot and may develop a small hole (perforation). A perforation lets stool leak into your belly, which can cause a life-threatening infection (peritonitis).

If you've had ulcerative colitis for a long time, you can have:

  • Skin rash

  • Mouth sores

  • Joint pain

  • Red, sore eyes

  • Problems with your liver and gallbladder

  • Low blood count (anemia)

  • Weight loss

  • Increased risk of colon cancer

How can doctors tell if I have ulcerative colitis?

Doctors will thread a thin, lighted tube with a small camera through your anus to look at your intestines (colonoscopy) to:

  • Look at how much inflammation there is

  • Take samples of mucus or stool

  • Remove tissue samples from inflamed areas and look at them under a microscope (biopsy)

Doctors may also do:

  • Blood tests

  • CT scan or MRI to help see what parts of the large intestine are affected

Sometimes it's hard for doctors to tell the difference between ulcerative colitis and Crohn disease of the colon because many of the symptoms are the same.

How do doctors treat ulcerative colitis?

There’s no cure for ulcerative colitis. Many treatments can help with symptoms.

Medicines may:

  • Help stop diarrhea and belly pain

  • Lessen inflammation in your intestine

  • Change the way your immune system works

Other treatments include:

  • Drinking enough fluids

  • Taking iron, calcium, and vitamin D supplements

  • Avoiding nuts and raw fruits and vegetables when you have a flare-up

  • Trying a dairy-free diet to see if it eases symptoms

  • Not taking certain medicines that can cause a flare-up such as painkillers called NSAIDs

  • Avoiding stress

If medicines don't work—or much later in order to lessen your risk of colon cancer—surgery may be done to remove your large intestine. Sometimes after surgery you have a ileostomy. An ileostomy is an opening in your lower belly connected to the end of your small intestine. Your stool comes out of the ileostomy into a plastic bag. Sometimes the doctor can do a special procedure that removes your colon but doesn't require an ileostomy.

If you haven't had surgery, doctors will do colonoscopy frequently to look for early signs of cancer.

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