Ulcerative colitis is a fairly common long term condition that causes inflammation in the colon. It is a form of inflammatory bowel disease (IBD) that is similar to Crohn’s disease.

The colon removes nutrients from undigested food and eliminates the waste products through the rectum and anus in the form of feces.

In severe cases, ulcers form on the lining of the colon. These ulcers may bleed, which produces pus and mucus.

According to the Genetics Home Reference library, an estimated 750,000 people in the United States have ulcerative colitis. This is equivalent to 40–240 in every 100,000 people.

In this article, we cover the symptoms, risk factors, and possible causes of ulcerative colitis, as well as some treatment options.

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Abdominal pain is a common symptom of ulcerative colitis.

The first symptom of ulcerative colitis is usually diarrhea.

Feces becomes progressively looser, and there may be abdominal pain with cramps and a severe urge to pass stools.

Diarrhea may begin slowly or suddenly. Symptoms depend on the extent and spread of inflammation.

The most common symptoms of ulcerative colitis include:

  • abdominal pain
  • bloody diarrhea with mucus

The following might also occur:

Symptoms are often worse early in the morning.

Symptoms may be mild or absent for months or years at a time. However, they will usually return without treatment and vary depending on the affected part of the colon.

Symptoms may vary depending on the area of inflammation.

In the sections below, we discuss the types of ulcerative colitis, many of which affect different parts of the colon:

Ulcerative proctitis

This type affects only the end of the colon, or the rectum. Symptoms tend to include:

  • rectal bleeding, which may be the only symptom
  • rectal pain
  • an inability to move the bowels, despite frequent urges

Ulcerative proctitis is usually the mildest type of ulcerative colitis.


This involves the rectum and the sigmoid colon, which is the lower end of the colon.

Symptoms include:

  • bloody diarrhea
  • abdominal cramps
  • abdominal pain
  • a constant urge to pass stool

Left sided colitis

This affects the rectum and the left side of the sigmoid and descending colon.

Symptoms usually include:

  • bloody diarrhea
  • abdominal cramping on left side
  • weight loss


This affects the whole colon. Symptoms include:

  • occasionally severe, bloody diarrhea
  • abdominal pain and cramps
  • fatigue
  • considerable weight loss

Fulminant colitis

This is a rare, potentially life threatening form of colitis that affects the whole colon.

Symptoms tend to include severe pain and diarrhea, which can lead to dehydration and shock.

Fulminant colitis can present a risk of colon rupture and toxic megacolon, which causes the colon to become severely distended.

Some dietary measures may help relieve symptoms, including:

  • eating smaller, more regular meals, such as five or six small meals per day
  • drinking plenty of fluids, especially water, to prevent dehydration
  • avoiding caffeine and alcohol, which can both increase diarrhea
  • avoiding sodas, which can increase gas
  • keeping a food diary to identify which foods make symptoms worse

A doctor may suggest temporarily following a specific diet depending on symptoms, such as:

  • a low fiber diet
  • a lactose free diet
  • a low fat diet
  • a low salt diet

It may help to take supplements or eliminate particular foods from the diet. However, a person should discuss any complementary or alternative measures with a doctor before trying them.

The exact causes of ulcerative colitis are unclear. However, they may involve the following:


About one-fifth of people with ulcerative colitis have a close relative who has the same condition, suggesting that it is heritable.


The following environmental factors might affect the onset of ulcerative colitis:

  • diet
  • air pollution
  • cigarette smoke
  • poor hygiene

Immune system

The body might respond to a viral or bacterial infection in a way that causes the inflammation associated with ulcerative colitis.

Once the infection resolves, the immune system continues to respond, which leads to ongoing inflammation.

Another theory suggests that ulcerative colitis may be an autoimmune condition. A fault in the immune system may cause it to fight nonexistent infections, leading to inflammation in the colon.

Some known risk factors for ulcerative colitis include:

  • Age: Ulcerative colitis can affect people at any age but is more common at 15–30 years of age.
  • Ethnicity: White people have a higher risk of developing the condition, as do those of Ashkenazi Jewish descent.
  • Genetics: Although recent studies have identified certain genes that may play a role in ulcerative colitis, the link is unclear due to the role of environmental factors.

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A colonoscopy can help a doctor diagnose ulcerative colitis.

A doctor will ask about a person’s symptoms and medical history. They will also ask whether any close relatives have had ulcerative colitis, IBD, or Crohn’s disease.

They will also check for signs of anemia, or low levels of iron in the blood, and tenderness around the abdomen.

Several tests can help rule out other possible conditions and diseases, including Crohn’s disease, infection, and irritable bowel syndrome.

These include:

  • blood tests
  • stool tests
  • X-ray
  • barium enema, during which a healthcare professional passes a fluid called barium through the colon to show any changes or anomalies in a scan
  • sigmoidoscopy, in which a healthcare professional inserts a flexible tube with a camera at the end, called an endoscope, into the rectum
  • colonoscopy, wherein a doctor examines the whole colon using an endoscope
  • a CT scan of the abdomen or pelvis

A person with ulcerative colitis will need to see a doctor who specializes in treating conditions of the digestive system, or a gastroenterologist.

They will assess the type and severity of the condition and create a treatment plan.

People with severe symptoms may require hospitalization, but a person with mild-to-moderate symptoms will most likely need outpatient treatment.

Treatment will focus on:

  • managing active symptoms until they go into remission
  • maintaining remission to prevent further symptoms

Managing active ulcerative colitis

Treatment will involve the use of several types of medication. We discuss these in the following sections:

5-aminosalicylic acid

This is the standard treatment option for ulcerative colitis. Aminosalicylates tend to be effective in reducing inflammation.

They often come in pill form, but doctors sometimes prescribe them as suppositories. For those who have an allergy to sulfa, there are also sulfa free forms available.

The main forms include:

  • mesalamine
  • balsalazide
  • sulfasalazine

Side effects might include:


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Steroids can help a person with severe symptoms of ulcerative colitis.

If the symptoms become severe or do not respond to aminosalicylates, a doctor may prescribe steroids. These can also reduce inflammation.

Prolonged use of steroids, especially oral steroids, can have serious side effects. A doctor will usually recommend discontinuing steroid treatment as soon as the condition responds.

Side effects include:

Long term adverse effects include a higher risk of:

If other treatments have not been effective, or when the gastroenterologist needs to discontinue steroids, immunosuppressants may help relieve symptoms. These reduce immune activity and soothe inflammation in the colon and rectum.

People tend to use an immunosuppressant called azathioprine to treat ulcerative colitis.

Possible side effects include:

  • nausea
  • diarrhea
  • liver damage
  • anemia
  • bruising
  • infections


Doctors may prescribe antitumor necrosis factor agents to bring about remission.

These include:

  • infliximab (Remicade)
  • adalimumab (Humira)
  • golimumab (Simponi)
  • Vedolizumab (Entyvio), a different biologic that targets the gut mucosal immune system


Xeljanz is a Janus kinase inhibitor. Studies have shown that it can bring about remission more effectively than corticosteroids.

In 2018, the Food and Drug Administration (FDA) approved 5- and 10-milligram doses of Xeljanz twice per day for the treatment of this type of ulcerative colitis.

Possible adverse effects include diarrhea, high cholesterol, and shingles. Anyone who experiences adverse effects when taking Xeljanz should speak to their doctor.

Managing severe active ulcerative colitis

Hospitalization will often be necessary due to the risk of malnutrition, dehydration, and life threatening complications such as colon rupture.

Treatment includes intravenous fluids and medications.

Maintaining remission

As soon as symptoms are in remission, taking regular doses of aminosalicylate can help prevent recurrences. If recurrences occur regularly despite treatment with aminosalicylate, the gastroenterologist may prescribe azathioprine.

People with extensive ulcerative colitis may need long term maintenance therapy. If the person goes into remission for 2 years without a recurrence, the doctor might adjust this course of treatment.

Having a support system with experience and empathy can be vital for helping people cope with ulcerative colitis.

IBD Healthline is a free app for people with the condition. The app is available on the AppStore and Google Play. Download it here.


If other treatments do not provide relief, surgery may be an option.

Some surgical options include:

  • Colectomy: A surgeon removes part or all of the colon.
  • Ileostomy: A surgeon makes an incision in the stomach, extracts the end of the small intestine, and connects it to an external pouch, called a Kock pouch. The pouch then collects waste material from the intestine.
  • Ileoanal pouch: A surgeon constructs a pouch from the small intestine and connects it to the muscles surrounding the anus. The ileoanal pouch is not an external pouch.

The possible complications of ulcerative colitis range from a lack of nutrients to potentially fatal bleeding from the rectum. We cover more possible complications in the sections below:

Colorectal cancer

Ulcerative colitis, especially if symptoms are severe or extensive, increases the risk of developing colon cancer.

According to the National Institute of Diabetes and Digestive and Kidney Diseases, colon cancer risk is highest when ulcerative colitis affects the entire colon for longer than 8 years.

Males with ulcerative colitis also have a higher risk of colon cancer than females with the condition.

Toxic megacolon

This complication occurs in a few cases of severe ulcerative colitis.

In toxic megacolon, gas becomes trapped, causing the colon to swell. When this occurs, there is a risk of colon rupture, septicemia, and shock.

Other complications

Other possible complications of ulcerative colitis include:

  • inflammation of the skin, joints, and eyes
  • liver disease
  • osteoporosis
  • perforated colon
  • severe bleeding
  • severe dehydration

To prevent a loss of bone density, a doctor may prescribe vitamin D supplements, calcium, or other medications.

Attending regular medical appointments, closely following a doctor’s advice, and being aware of symptoms can help prevent the development of these complications.