People may experience fever as a symptom of ulcerative colitis (UC) or as a complication of the condition. A person should consult a gastroenterologist to determine the possible cause and a suitable treatment plan.

UC is a type of inflammatory bowel disease (IBD) that usually causes gastrointestinal symptoms. However, people may also have symptoms that affect other body parts and experience more generalized symptoms, such as fever and chills.

This article explores the link between UC and fever. It also discusses how to treat fever and when to consult a doctor.

A person holding a thermometer with a selection of tablets on the tableShare on Pinterest
Maryna Terletska/Getty Images

Fever is the body’s typical response to infection and inflammation. Experts commonly associate it with severe UC and the possible complications that may arise. However, some people with a mild case of the condition may still experience fever as a symptom.

UC symptoms

UC is a lifelong condition that causes inflammation of the large intestine. It commonly begins in the rectum and spreads upward to the colon.

Many people with IBD may experience fever as one of the symptoms, which often start gradually.

A person will likely experience alternating periods of remission, during which they have few or no symptoms, and flare-ups, when the disease is active.

Some of the main symptoms include:

Severe colitis

Fever is often a sign of volume depletion and toxicity. Other possible signs and symptoms include:

Fulminant colitis

Fulminant colitis is a subtype of severe UC that produces signs of increased toxicity, including fever and unintentional weight loss. The condition can also cause:

  • more than 10 stools per day
  • abdominal pain
  • distension
  • continuous bleeding

Toxic megacolon

Fever can also indicate the presence of complications. One common complication associated with fulminant colitis is toxic megacolon. This condition involves the large intestine losing muscle tone within days to hours, causing it to expand. This may cause a high fever and abdominal pain.

Other causes

A person may also develop a fever as a side effect of taking medications that treat UC, including vedolizumab (Entyvio).

Sometimes, UC can also be the underlying cause of fevers of unknown origin, as fever can present without other accompanying symptoms.

People should speak with a doctor to determine what may be causing their symptoms.

The treatment of UC depends on the extent and severity of the disease. The first-line treatment is anti-inflammatory medications, such as sulfasalazine and 5-aminosalicylates.

Gastroenterologists may also add immunosuppressants such as azathioprine and cyclosporine if a person does not respond to their initial treatment.

If a person’s fever results from fulminant colitis or toxic megacolon, they may require hospitalization. In the hospital, they will receive IV fluids and electrolytes. Doctors administer these medications directly into the bloodstream.

The doctor may also give high dose IV corticosteroids or cyclosporine to manage the condition. This may be alongside antibiotics or infliximab, depending on a person’s response to the drugs.

Learn more about treating UC.

A doctor may also recommend bowel rest, which requires a person to refrain from eating food by mouth. This gives the digestive system time to heal. A person may have a nasogastric tube fitted to help decompress the stomach.

A person may need surgery in severe cases and if the symptoms do not improve within 24–48 hours. Doctors may recommend a subtotal colectomy with ileostomy and one of the below:

  • a Hartmann pouch
  • rectostomy
  • sigmoidostomy

Learn more about surgery for UC.

A person should consult a doctor immediately if they are experiencing:

  • new or increased bleeding
  • constant abdominal pain
  • a high, persistent fever
  • symptoms that persist or worsen
  • new symptoms

Fever is the body’s response to inflammation. As UC is a type of IBD, this may be one of the symptoms a person experiences as part of the body’s inflammatory response.

However, doctors more often associate it with severe or more extensive UC. It may also be a side effect of medications or other associated complications.

A person with UC who experiences high or persistent fever with or without other symptoms should contact a doctor for a prompt diagnosis and treatment.