A person with ulcerative colitis (UC) who experiences frequent bowel movements or bloody diarrhea for more than 3 days may require hospitalization.

People living with UC may also experience flare-ups or complications if the condition is left untreated. As such, it is advisable to go to hospital if people develop these symptoms.

This article will explain the symptoms, complications, and treatments of UC. It also looks at the outlook for those with the condition and when they should go to the hospital.

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UC is a form of inflammatory bowel disease (IBD). A person should consult a doctor if they experience symptoms of UC and have never had it diagnosed. If symptoms persist or are severe, people should seek medical attention.

The symptoms of UC include:

  • recurring diarrhea, which may contain mucus or blood
  • frequent need to empty the bowels
  • abdominal pain
  • fatigue
  • weight loss

A person may need admission to the hospital for further tests and treatment if symptoms are severe and doctors cannot help manage them as an outpatient.

A person with a previous UC diagnosis should contact their gastroenterologist if they suspect a flare-up.


People with UC may experience episodes of mild symptoms, periods of few or no symptoms (known as remission), or flare-ups. A person can usually treat mild and moderate flare-ups at home.

However, the most severe flare-ups may require hospitalization to minimize the risk of dehydration or other potentially severe complications.

Signs of a flare-up include:

  • frequent bowel movements, such as more than five times in 24 hours
  • loose stool
  • diarrhea with blood or mucus for more than 3 days
  • fever
  • waking up at night to have a bowel movement

A person may also experience nongastrointestinal symptoms, which could cause:

Doctors will assess a person’s symptoms, general health, and medical history.

Physical examinations will also check for signs such as abdominal tenderness and anemia. Other tests involve the examination of a stool sample and blood tests.

Further tests may include:

  • Imaging tests: These tests may include an X-ray and CT scan to obtain a detailed visual of a person’s colon and rectum and rule out other serious complications.
  • Sigmoidoscopy: This test evaluates the level and extent of bowel inflammation in the lower portion of the colon. During this test, the doctor will insert a flexible tube with a camera connected to it to collect a sample of bowel tissue, known as a biopsy.
  • Colonoscopy: This test can help evaluate the entirety of the colon. The doctor will insert a tube with a camera inside the rectum during this test.


The treatment depends on the severity of a person’s condition. The aim of treatment is usually to reduce symptoms and induce remission.

The treatment for the onset or flare-up of UC may include:

Adequate nutritional support is also an important part of managing UC symptoms.

Read more about UC types and treatments.

How long will a person stay in the hospital?

The time a person will stay in the hospital depends on the severity of their UC. Doctors usually discharge a person when symptoms respond to the treatment within a few days to a few weeks.

Medical professionals will take different samples to monitor the inflammation. They will also keep track of the consistency of the stool and the frequency of the bowel movements.

Doctors will allow a person with UC to leave the hospital when they are stable and can manage their symptoms at home.

Doctors do not know the exact cause of UC. However, research suggests potential causes of UC may include:

  • A dysregulated autoimmune response: This response occurs when a person’s immune system, which usually defends their body against infections, mistakenly attacks the good bacteria. The bacteria usually help digestion and live inside the colon, but the immune system mistakes them for being an infection. This response leads to an inflammation of the colon and rectum. Learn more about UC as an autoimmune disease.
  • Genetics: This occurs in people with certain types of genes. Among people with UC, 8–14% have a family history of IBD, and having a first-degree relative with the condition makes someone four times more likely to develop it. Read more about genetics and UC.
  • Environmental factors: Certain environmental factors may increase the risk of developing UC, such as:
    • pollution
    • medication
    • certain types of diets

Find out about possible environmental factors linked to UC.

UC may lead to other potential complications that can result in hospitalization. If severe UC symptoms are left untreated, the following conditions may develop:

Perforated colon

Long-term colon inflammation may lead to perforation of the intestinal wall. This perforation can allow bacteria to leak into a person’s abdomen, causing peritonitis.

Peritonitis is a serious condition that can lead to blood poisoning and sepsis, a potentially fatal infection.

The symptoms of colon perforation may include:

A person with a perforated colon requires immediate medical attention. Doctors will conduct surgery to open the abdomen and immediately repair the hole in the intestines. This procedure is known as a laparotomy.

If a person experiences sepsis, they will require urgent medical treatment with IV fluids and antibiotics.

Read more about perforated colon causes and treatment.

Fulminant colitis

Fulminant colitis is uncommon but may occur in a small portion of people with severe UC who have:

  • more than 10 stools per day
  • continuous bleeding in their stool
  • abdominal pain
  • abdominal distention, or stomach swelling
  • fever
  • anorexia

Fulminant colitis is a medical emergency, and a person with its symptoms needs immediate hospitalization. Doctors usually treat fulminant colitis with IV medications or surgery.

Read more about colon surgery.

Toxic megacolon

Toxic megacolon is a serious and rare complication of UC. This condition may result in the enlargement of the colon. This can cause the rupture of the colon and septicemia as a consequence. Therefore, it requires immediate hospitalization.

The symptoms of toxic megacolon may include:

Treatment options for toxic megacolon include:

  • IV fluids
  • IV steroids
  • IV antibiotics
  • bowel rest
  • nasogastric compression to help release air from the bowel

Doctors will perform emergency surgery if people show signs of:

The usual surgical procedure for toxic megacolon involves subtotal or total colectomy (partial or total removal of the affected area) and ileostomy (creating an opening in the abdominal wall to release stool).

Learn more about colectomy versus ileostomy.

Rectal bleeding

Rectal bleeding occurs in most people with UC in varying amounts. This symptom usually results from ulcers in the lining of the large intestine. This symptom may lead to anal fissures or hemorrhoids.

Severe bleeding is uncommon, but a person must seek medical attention immediately.

Treatment for rectal bleeding depends on the specific cause, but doctors usually prescribe anti-inflammatory drugs to treat UC and bleeding.

Learn more about UC and rectal bleeding.

If hemorrhoids are causing rectal bleeding, medical professionals may treat them with the following:

People can treat most fissures with remedies such as:

Primary sclerosing cholangitis

This condition is a possible complication of UC, consisting of the inflammation of a person’s bile ducts. Primary sclerosing cholangitis does not usually cause symptoms before it reaches an advanced stage.

The symptoms of primary sclerosing cholangitis may include:

Currently, there is no treatment for primary sclerosing cholangitis. The most severe cases of primary sclerosing cholangitis may require a liver transplant.

Bowel cancer

People with active UC have a higher risk of developing bowel cancer. Some of the symptoms of bowel cancer may overlap with those of UC, so a person should try to seek a prompt diagnosis to start a course of treatment.

Due to the risk, even without symptoms, doctors recommend that people with UC have a screening colonoscopy 8 years after first developing symptoms and then every 1–3 years, depending on the severity of the disease.

Bowel cancer treatment may include:

Various methods help control symptoms and reduce the risk of developing complications that require hospitalization. These include:

  • eating five or six smaller meals per day
  • drinking plenty of fluids
  • taking dietary supplements
  • keeping a food diary to find out whether certain types of food make the symptoms of UC worse
  • eating a low residue, or low fiber, diet
  • exercising
  • relieving stress, where possible, with relaxation techniques

Before changing their diet, a person with UC should consult a gastroenterologist or nutritionist.

UC may affect people differently. Some may remain in remission, while others may experience a flare-up of symptoms. Doctors usually prescribe medications to control the symptoms of UC.

A person with UC may develop serious complications if symptoms become severe or are left untreated. This may require immediate medical treatment in a hospital. If a person with severe symptoms does not respond to the usual line of treatment, doctors may need to perform surgery.

Lifestyle changes may help control and reduce the frequency of a person’s flare-ups. People can consult their gastroenterologist for management and treatment options.