Ulcerative Colitis

National Digestive Diseases Information Clearinghouse

What is ulcerative colitis (UC)?

Ulcerative colitis is a chronic, or long-lasting, 

disease that causes inflammation and sores, 

called ulcers, in the inner lining of the large 

intestine, which includes the colon and the 

rectum––the end part of the colon.

UC is one of the two main forms of chronic 

inflammatory disease of the gastrointestinal 

tract, called inflammatory bowel disease 

(IBD). The other form is called Crohn’s 

disease. 

Normally, the large intestine absorbs water 

from stool and changes it from a liquid to a 

solid. In UC, the inflammation causes loss of 

the lining of the colon, leading to bleeding, 

production of pus, diarrhea, and abdominal 

discomfort. 

What causes UC?

The cause of UC is unknown though theories 

exist. People with UC have abnormalities 

of the immune system, but whether these 

problems are a cause or a result of the 

disease is still unclear. The immune system 

protects people from infection by identifying 

and destroying bacteria, viruses, and other 

potentially harmful foreign substances. With 

UC, the body’s immune system is believed 

to react abnormally to bacteria in the digestive tract. UC sometimes runs in families 

and research studies have shown that certain 

gene abnormalities are found more often in 

people with UC. 

sensitivity to certain foods or food products 

does not cause UC, it may trigger symptoms 

in some people. 

UC is not caused by emotional distress, but 

the stress of living with UC may contribute to 

a worsening of symptoms. In addition, while 

What are the symptoms of UC?

The most common symptoms of UC are 

abdominal discomfort and blood or pus in 

diarrhea. Other symptoms include

•	 anemia 

•	 fatigue 

•	 fever

•	 nausea

•	 weight loss 

•	 loss of appetite 

•	 rectal bleeding 

•	 loss of body fluids and nutrients 

•	 skin lesions 

•	 growth failure in children 

Most people diagnosed with UC have mild 

to moderate symptoms. About 10 percent 

have severe symptoms such as frequent fevers, 

bloody diarrhea, nausea, and severe abdominal cramps.1 UC can also cause problems 

such as joint pain, eye irritation, kidney 

stones, liver disease, and osteoporosis. Scientists do not know why these problems occur, 

but they think these complications may be 

the result of inflammation triggered by the 

immune system. Some of these problems go 

away when UC is treated.

1Doherty GA, Cheifetz AS. Management of 

acute severe ulcerative colitis. Expert Review of 

Gastroenterology and Hepatology. 2009;3(4):395–405.
 

 

 

 

 

 

 

 

 

 

 

 

Who develops UC? 

While UC can occur in people of any age, 

it usually develops between the ages of 

15 and 302 and less frequently between the 

ages of 60 and 80.3 The disease affects men 

and women equally. People with a family 

member or first-degree relative with an IBD 

are at higher risk for developing UC, as are 

Caucasians and people of Jewish descent. 

2Garud S, Peppercorn MA. Ulcerative colitis: current 

treatment strategies and future prospects. Therapeutic 

Advances in Gastroenterology. 2009;2(2):99–108. 

3Inflammatory bowel disease. In: Fauci AS, 

Braunwald E, Kasper DL, et al., eds. Harrison’s 

Principles of Internal Medicine. 17th ed. New York: 

McGraw-Hill Companies; 2008: 1886–1903. 

How is UC diagnosed? 

Ulcerative colitis can be difficult to diagnose 

because its symptoms are similar to those 

of other intestinal disorders and to Crohn’s 

disease. Crohn’s disease differs from UC 

in that Crohn’s disease causes inflammation 

deeper within the intestinal wall and can 

occur in other parts of the digestive system, 

including the small intestine, mouth, esophagus, and stomach. 

People with suspected UC may be referred 

to a gastroenterologist, also called a gastroenterological specialist, a doctor who specializes in digestive diseases. A physical exam 

and medical history are usually the first steps 

in diagnosing UC, followed by one or more 

tests and procedures: 

• Blood tests. A blood test involves drawing blood at a health care provider’s 

office or commercial facility and sending the sample to a lab for analysis. The 

blood test can show a high white blood 

cell (WBC) count, which is a sign of 

inflammation somewhere in the body. 

Blood tests can also detect anemia, 

which could be caused by bleeding in 

the colon or rectum. 

Liver 

Small 

intestine Anus 

Rectum 

Colon 

(shaded) 

Stomach 

• Stool test. Stool tests can show WBCs, 

which indicate UC or another IBD. 

The doctor will give the person a pan 

and a container for catching and storing 

the stool. The sample is returned to the 

health care provider or a commercial 

facility and sent to a lab for analysis. 

The sample also allows doctors to detect 

bleeding or infection in the colon or 

rectum caused by bacteria, a virus, or 

parasites. 

• Flexible sigmoidoscopy and colonoscopy. 

These tests are the most accurate 

methods for diagnosing UC and ruling 

out other possible conditions, such as 

Crohn’s disease, diverticular disease, or 

cancer. The tests are similar, but colonoscopy is used to look inside the rectum 

and entire colon, while flexible sigmoidoscopy is used to look inside the rectum 

and lower colon. For both tests, the 

doctor will provide written bowel prep 

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instructions to follow at home before the 

test. The person may be asked to follow 

a clear liquid diet for 1 to 3 days before 

the test. A laxative may be required 

the night before the test. One or more 

enemas may be required the night before 

and about 2 hours before the test. 

For both tests, the person lies on a table 

while the doctor inserts a flexible tube 

into the anus. A small camera on the 

tube sends a video image of the intestinal lining to a computer screen. The 

doctor can see inflammation, bleeding, 

or ulcers on the colon wall. The doctor 

may also perform a biopsy by snipping 

a bit of tissue from the intestinal lining. The person will not feel the biopsy. 

The doctor will look at the tissue with 

a microscope to confirm the diagnosis. 

These tests are performed at a hospital 

or outpatient center by a gastroenterologist. In most cases, a light sedative, and 

possibly pain medication, helps people 

relax. The test can show problems in the 

rectum or lower colon that may be causing symptoms. 

Cramping or bloating may occur during the first hour after the test. Driving 

is not permitted for 24 hours after the 

test to allow the sedative time to wear 

off. Before the appointment, a person 

should make plans for a ride home. Full 

recovery is expected by the next day. 

• Computerized tomography (CT) scan 

and barium enema x ray. A CT scan uses 

a combination of x rays and computer 

technology to create three-dimensional 

(3-D) images. A CT scan may include 

the injection of a special dye, called 

contrast medium. CT scans require the 

person to lie on a table that slides into 

a tunnel-shaped device where the x rays 

are taken. The procedure is performed 

in an outpatient center or hospital by 

an x-ray technician, and the images are 

interpreted by a radiologist––a doctor who 

specializes in medical imaging; anesthesia is not needed. A barium enema x ray 

involves the injection of contrast medium, 

called barium, into the colon to make the 

colon, rectum, and lower part of the small 

intestine more visible in x-ray images. The 

procedure is performed in a hospital or 

outpatient center by an x-ray technician, 

and the images are interpreted by a radiologist; anesthesia is not needed. These 

tests can show physical abnormalities and 

are sometimes used to diagnose UC. 

How is UC treated? 

Treatment for UC depends on the severity of 

the disease and its symptoms. Each person 

experiences UC differently, so treatment is 

adjusted for each individual. 

Medication Therapy 

While no medication cures UC, many can 

reduce symptoms. The goals of medication 

therapy are to induce and maintain remission–– 

periods when the symptoms go away for 

months or even years––and to improve quality 

of life. Many people with UC require medication therapy indefinitely, unless they have 

their colon and rectum surgically removed. 

The type of medication prescribed depends on 

the severity of the UC. 

• Aminosalicylates, medications that 

contain 5-aminosalicyclic acid (5-ASA), 

help control inflammation. One medication, sulfasalazine (Azulfidine), is a 

combination of sulfapyridine and 5-ASA. 

The sulfapyridine component carries the 

anti-inflammatory 5-ASA to the intestine. 

Sulfapyridine may lead to side effects such 

as nausea, vomiting, heartburn, diarrhea, 

and headache. Other 5-ASA agents, such 

as olsalazine (Dipentum), mesalamine 

(Asacol, Canasa, Lialda, Rowasa), and 

balsalazide (Colazal), cause fewer side 

effects, and can be used by people who 

3 Ulcerative Colitis 
4    Ulcerative Colitis

cannot take sulfasalazine.  Depending 

on which parts of the colon and rectum 

are affected by UC, 5-ASAs can be given 

orally; through a rectal suppository, a 

small plug of medication inserted in the 

rectum; or through an enema––liquid 

medication put into the rectum.  Unless 

the UC symptoms are severe, people are 

usually first treated with aminosalicylates.  These medications are also used 

when symptoms return after a period of 

remission.  

• Corticosteroids, such as prednisone, 

methylprednisone, and hydrocortisone, 

also reduce inflammation.  They are 

used for people with more severe symptoms and people who do not respond 

to 5-ASAs.  Corticosteroids, also known 

as steroids, can be given orally, intravenously, or through an enema, a rectal 

foam, or a suppository, depending on 

which parts of the colon and rectum are 

affected by UC.  Side effects include 

weight gain, acne, facial hair, hypertension, diabetes, mood swings, bone mass 

loss, and an increased risk of infection.  

Because of harsh side effects, steroids 

are not recommended for long-term 

use.  Steroids are usually prescribed for 

short-term use and then stopped once 

inflammation is under control.  The other 

UC medications are used for long-term 

symptom management.

• Immunomodulators, such as azathioprine 

(Imuran, Azasan), 6-mercaptopurine 

(6-MP) (Purinethol), and cyclosporine 

(Neoral, Sandimmun, Sandimmune), 

suppress the immune system.  These 

medications are prescribed for people 

who do not respond to 5-ASAs.  Immunomodulators are given orally, but 

they are slow-acting and can take 3 to 

6 months to take effect.  People taking 

these medications are monitored for 

complications including nausea, vomiting, 

fatigue, pancreatitis, hepatitis, a reduced 

WBC count, and an increased risk of infection.  Cyclosporine is only used with severe 

UC, because one of its frequent side effects 

is toxicity, which means it can cause harmful effects to the body over time.

• Infliximab (Remicade) is an anti-tumor 

necrosis factor (anti-TNF) agent prescribed 

to treat people who do not respond to the 

other UC medications or who cannot take 

5-ASAs.  People taking Infliximab should 

also take immunomodulators to avoid 

allergic reactions.  Infliximab targets a 

protein called TNF that causes inflammation in the intestinal tract.  The medication 

is given through intravenous infusion—

through a vein—every 6 to 8 weeks at a 

hospital or outpatient center.  Side effects 

may include toxicity and increased risk of 

infections, particularly tuberculosis.

Other medications may be prescribed to 

decrease emotional stress or to relieve pain, 

reduce diarrhea, or stop infection. 

Hospitalization

Sometimes UC symptoms are severe enough 

that a person must be hospitalized.  For 

example, a person may have severe bleeding or 

diarrhea that causes dehydration.  In such cases, 

health care providers will use intravenous fluids 

to treat diarrhea and loss of blood, fluids, and 

mineral salts.  People with severe symptoms may 

need a special diet, tube feeding, medications, 

or surgery.

Surgery

About 10 to 40 percent of people with UC 

eventually need a proctocolectomy––surgery 

to remove the rectum and part or all of the 

colon.1  Surgery is sometimes recommended if 

medical treatment fails or if the side effects of 

corticosteroids or other medications threaten a 

person’s health.  Other times surgery is performed because of massive bleeding, severe 

illness, colon rupture, or cancer risk.  Surgery is 

performed at a hospital by a surgeon; anesthesia 

will be used.  Most people need to remain in the 
5    Ulcerative Colitis

hospital for 1 to 2 weeks, and full recovery can 

take 4 to 6 weeks.

A proctocolectomy is followed by one of the 

following operations:

• Ileoanal pouch anastomosis, also called 

“pouch surgery,” makes it possible for 

people with UC to have normal bowel 

movements, because it preserves part 

of the anus.  For this operation, the 

surgeon preserves the outer muscles 

of the rectum during the proctocolectomy.  The ileum––the lower end of the 

small intestine––is then pulled through 

the remaining rectum and joined to the 

anus, creating a pouch.  Waste is stored 

in the pouch and passes through the 

anus in the usual manner.  Bowel movements may be more frequent and watery 

than before the procedure.  Inflammation of the pouch, called pouchitis, is 

a possible complication and can lead 

to symptoms such as increased diarrhea, rectal bleeding, and loss of bowel 

control.  Pouch surgery is the first type 

of surgery considered for UC because it 

avoids a long-term ileostomy.

Ileal reservoir

Rectal cuff

Anal 

sphincter

Ileum

Anus

Ileoanal pouch anastomosis

• Ileostomy is an operation that attaches 

the ileum to an opening made in the 

abdomen, called a stoma.  The stoma is 

about the size of a quarter and is usually 

located in the lower right part of the 

abdomen near the beltline.  An ostomy 

pouch is then attached to the stoma and 

worn outside the body to collect stool.  

The pouch needs to be emptied several 

times a day.  An ileostomy performed 

for UC is usually permanent.  A specially trained nurse will teach the person 

how to clean, care for, and change the 

ostomy pouch and how to protect the 

skin around the stoma.

The type of surgery recommended will be 

based on the severity of the disease and the 

person’s needs, expectations, and lifestyle.  

People faced with this decision should get as 

much information as possible by talking with 

their doctors; enterostomal therapists, nurses 

who work with colon surgery patients; other 

health care professionals; and people who 

have had colon surgery.  Patient advocacy 

organizations can provide information about 

support groups and other resources.  

Eating, Diet, and Nutrition

Dietary changes may help reduce UC symptoms.  A recommended diet will depend on 

the person’s symptoms, medications, and 

reactions to food.  General dietary tips that 

may alleviate symptoms include

• eating smaller meals more often

• avoiding carbonated drinks

• eating bland foods

• avoiding high-fiber foods such as corn 

and nuts

For people with UC who do not absorb 

enough nutrients, vitamin and nutritional 

supplements may be recommended. 
 

Is colon cancer a concern 

with UC? 

People with UC have an increased risk 

of colon cancer when the entire colon is 

affected for a long period of time. For 

example, if only the lower colon and rectum 

are involved, the risk of cancer is no higher 

than that of a person without UC. But if the 

entire colon is involved, the risk of cancer 

is higher than the normal rate.4 The risk of 

colon cancer also rises after having UC for 

8 to 10 years and continues to increase over 

time. Effective maintenance of remission 

by treatment of UC may reduce the risk of 

colon cancer. Surgical removal of the colon 

eliminates the risk of colon cancer. 

With UC, precancerous changes––called 

dysplasia––sometimes occur in the cells lining the colon. People with dysplasia are at 

increased risk of developing colon cancer. 

Doctors look for signs of dysplasia when performing a colonoscopy or flexible sigmoidoscopy and when examining tissue removed 

during these procedures. 

According to the U.S. Preventive Services 

Task Force guidelines for colon cancer 

screening, people who have had IBD 

throughout the colon for at least 8 years and 

those who have had IBD in only the left side 

of the colon for 12 to 15 years should have a 

colonoscopy with biopsies every 1 to 2 years 

to check for dysplasia. Such screening has 

not been proven to reduce the risk of colon 

cancer, but it may help identify cancer early 

and improve prognosis. These guidelines 

were produced by an independent expert 

4Colorectal cancer: early detection. American 

Cancer Society website. www.cancer.org/Cancer/ 

ColonandRectumCancer/MoreInformation/ 

ColonandRectumCancerEarlyDetection/index. 

Updated June 14, 2011. Accessed August 3, 2011. 

6 Ulcerative Colitis 

panel and endorsed by numerous organizations, including the American Cancer 

Society, the American College of Gastroenterology, the American Society of Colon and 

Rectal Surgeons, and the Crohn’s & Colitis 

Foundation of America. 

Points to Remember 

• Ulcerative colitis (UC) is a chronic, 

or long-lasting, disease that causes 

inflammation and sores, called 

ulcers, in the inner lining of the 

colon and rectum. 

• Ulcerative colitis is one of the two 

main forms of chronic inflammatory disease of the gastrointestinal 

tract, called inflammatory bowel 

disease (IBD). 

• The most common symptoms of 

UC are abdominal discomfort and 

bloody diarrhea. 

• Flexible sigmoidoscopy and colonoscopy are the most accurate 

methods for diagnosing UC and 

ruling out other possible conditions, such as Crohn’s disease, 

diverticular disease, or cancer. 

• Treatment for UC depends on the 

severity of the disease and its symptoms. Each person experiences UC 

differently, so treatment is adjusted 

for each individual. Treatment may 

include medication therapy, hospitalization, or surgery to remove the 

rectum and part or all of the colon. 

• Most people with UC never 

develop colon cancer, but two factors that increase the risk are the 

duration of the disease and how 

much of the colon is affected. 
 

Hope through Research 

The National Institute of Diabetes and 

Digestive and Kidney Diseases (NIDDK), 

through the Division of Digestive Diseases and Nutrition, conducts and sup

ports research into many kinds of digestive 

disorders, including UC. Researchers are 

studying how and why the immune system 

is activated, how it damages the colon, and 

the processes involved in healing. Through 

this increased understanding, new and more 

specific therapies for UC can be developed. 

-

Participants in clinical trials can play a more 

active role in their own health care, gain 

access to new research treatments before 

they are widely available, and help others 

by contributing to medical research. For 

information about current studies, visit 

www.ClinicalTrials.gov. 

For More Information 

Crohn’s & Colitis Foundation of America 

386 Park Avenue South, 17th Floor 

New York, NY 10016 

Phone: 1–800–932–2423 

Email: info@ccfa.org 

Internet: www.ccfa.org 

Reach Out for Youth with Ileitis and 

Colitis, Inc. 

P.O. Box 857 

Bellmore, NY 11710 

Phone: 631–293–3102 

Email: info@reachoutforyouth.org 

Internet: www.reachoutforyouth.org 

United Ostomy Associations of America, Inc. 

P.O. Box 512 

Northfield, MN 55057–0512 

Phone: 1–800–826–0826 

Email: info@ostomy.org 

Internet: www.ostomy.org 

Acknowledgments 

Publications produced by the Clearinghouse 

are carefully reviewed by both NIDDK 

scientists and outside experts. This publication was originally reviewed by the Crohn’s & 

Colitis Foundation of America. 

7 Ulcerative Colitis 
You may also find additional information about this 

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medications. When prepared, this publication 

included the most current information available. 

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NIH Publication No. 12–1597

October 2011

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