Ulcerative colitis (UC) is an autoimmune bowel disease involving inflammation and ulcers in your large intestines. Acute severe UC is a complication that requires prompt hospitalization.

Acute severe UC causes severe bleeding in your intestines and more than six bloody stools per day. You might have additional signs or symptoms such as a high fever or a rapid heart rate.

Read on to learn more about acute severe UC, including its symptoms, treatment, and outlook.

Medical emergency

Acute severe UC is a medical emergency. Go to the nearest emergency room if you have UC and are experiencing heavy bleeding.

UC can cause symptoms such as:

Acute severe UC involves more than six bloody stools per day and:

UC is caused by an autoimmune reaction that leads to ulcers and inflammation in your gut. A combination of genetic and environmental factors may be involved. Factors such as changes to your intestinal microbiome and atypical formations in your gut immunity may also play a role, although research is ongoing.

Acute severe UC develops when severe flare-ups cause frequent and severe bleeding. Common triggers include:

  • stress
  • certain foods
  • certain medications
  • menstruation

Learn more about UC flare-ups.

UC is most commonly diagnosed in people who are 15–30 years old and 50–70 years old.

Research suggests that a quarter of people with UC experience acute severe UC at least once and that the same percentage require hospitalization for UC at some point.

Risk factors for the development of acute severe UC include:

  • young age
  • extensive progression of UC
  • inadequate healing of the mucosa (the inner lining of organs and body cavities)
  • smoking

Acute severe UC is a medical emergency that can lead to death if not promptly treated. With improved treatment, the 1-year mortality rate has declined to roughly 1%.

Some people need to have part of their large intestine removed to treat acute severe UC. This can lead to additional problems such as:

Doctors often use the Truelove and Witts severity index to differentiate severe UC from milder flare-ups. This index categorizes acute UC as mild, moderate, or severe based on the following factors:

MildModerateSevere
Daily bloody stoolsfewer than 44–6more than 6 with at least one of the below criteria
Amount of blood in stoolssmall amountmild to severevisible blood
Pulse over 90 beats per minutenonoyes
Temperature above 100°F (37.8°C)nonoyes
Hemoglobin levels under 100 g/Lnonoyes
Erythrocyte sedimentation rate over 30 mm per hournonoyes

A doctor might perform additional testing such as:

It’s critical to get medical attention if you develop potential symptoms of UC, such as blood in your stool or persistent diarrhea. Blood in your stool can indicate internal bleeding and requires emergency medical attention.

If you have a UC diagnosis, it’s important to get medical attention if your symptoms change or become worse.

Acute severe UC is a medical emergency that usually requires hospitalization.

The initial treatment will focus on correcting fluid and nutritional imbalances by giving you fluids through an IV. You’ll also likely receive medications to prevent blood clots.

Steroids given through an IV are the primary treatment, but up to 40% of people don’t respond to these medications.

If your symptoms don’t improve with steroids, you’ll likely be given either infliximab (Remicade, Inflectra, Renflexis) or cyclosporine as a rescue therapy.

If your condition doesn’t respond to rescue therapy, you may need an emergency colectomy (surgery to remove part of your large intestine). Roughly 30% of people with acute severe UC require a colectomy.

Doctors aren’t entirely sure what causes UC or how to prevent it. You can potentially prevent milder flare-ups by maintaining lifestyle habits such as:

  • keeping a food diary and tracking which foods may be linked to your flare-ups
  • limiting your fiber intake during flare-ups
  • eating small meals
  • exercising regularly
  • managing or reducing stress
  • speaking with your doctor about treatment options

You may be able to help prevent severe flare-ups by:

  • taking all your prescribed medication
  • staying current with checkups with your doctor
  • keeping track of your symptoms and contacting your doctor if any alarming symptoms occur

Learn more about managing UC flare-ups.

In a 2021 study using data from Norway, researchers found that the 20-year risk of colectomy for people with UC was 13%. The 20-year relative survival rate was 92.4%, meaning that people with UC were 92.4% as likely to live at least 20 years as people without the condition.

Additionally, in a 2022 study using data from the United Kingdom, researchers found the long-term quality of life wasn’t lower among people who received a colectomy than among people treated with medications alone.

Here are some frequently asked questions people have about UC.

What are the four stages of ulcerative colitis?

UC is staged based on how much bleeding you have. The stages are mild, moderate, severe, and fulminant. The fulminant stage is a substage of severe UC involving bloody diarrhea, elevated heart rate, and severe anemia.

How serious is acute severe ulcerative colitis?

Acute severe UC is a medical emergency that requires prompt medical attention.

What is the life expectancy of a person with ulcerative colitis?

A 2020 study found that life expectancy was 6.6–8.1 years lower in females with UC or Crohn’s disease than in people without those conditions. And in males with either condition, life expectancy was 5.0–6.1 years lower than in people without those conditions.

What is the end stage of ulcerative colitis?

The most severe stage of UC is the fulminant stage. This stage causes severe anemia that can make it difficult to perform everyday tasks.

Acute severe UC is a serious complication of UC. It causes more than six bloody stools per day and can cause other symptoms such as fever and high heart rate.

Acute severe UC requires immediate hospitalization. It can often be managed with medications, but some people need to have part of their large intestine removed to treat this condition.