What Is Ulcerative Colitis?

What Is Ulcerative Colitis?

Ulcerative colitis (UC) is a condition in which the lining of the colon, or large intestine, becomes inflamed and develops sores that lead to bleeding and diarrhea. It usually affects the rectum and lower part of the colon, but it can affect the entire colon. Ulcerative colitis is a type of inflammatory bowel disease (IBD).

It’s thought that ulcerative colitis is a form of autoimmune disease.

Types of Ulcerative Colitis

Types of Ulcerative Colitis

There are five different types of ulcerative colitis:

  • Ulcerative proctitis: Inflammation is confined to the rectum, usually affecting less than 6 inches of it. Ulcerative proctitis is not associated with increased cancer risk. Symptoms of ulcerative proctitis usually include rectal bleeding and pain, and urgency with bowel movements (BMs).
  • Left-sided colitis: Inflammation begins at the rectum and goes up the colon into the splenic flexure, which is a bend in the colon near the spleen. Symptoms of left-sided colitis include bloody diarrhea, weight loss, loss of appetite, and pain on the left side of the abdomen.
  • Proctosigmoiditis: This is a form of left-sided colitis that only affects the rectum and the lower end of the colon, known as the sigmoid colon. Symptoms of proctosigmoiditis are similar to those of left-sided colitis.
  • Pancolitis: Inflammation affects the entire colon and causes severe ulcerative colitis. Pancolitis symptoms include bloody diarrhea, abdominal pain, loss of appetite, and weight loss.
  • Rectal-sparing UC: Rarely, UC can affect the entire colon while the rectum remains unaffected, with no inflammation.

Signs & Symptoms of Ulcerative Colitis


Ulcerative colitis symptoms vary from person to person. About half of patients report only mild symptoms.

Symptoms of ulcerative colitis can include:

  • Mild diarrhea, which may or may not be bloody; you may experience up to four episodes of urgent or loose bowel movements each day
  • Mild abdominal cramps
  • Straining with bowel movements
  • Occasional bouts of constipation

Moderate symptoms of ulcerative colitis are:

  • Persistent diarrhea, with more than four episodes of bloody, loose stool a day
  • Anemia, which is caused by intestinal bleeding lowering your red blood cell count; you may feel tired or weak
  • Mild to moderate abdominal pain
  • A low-grade fever

If you have severe disease, you may experience more severe symptoms:

  • At least six episodes of bloody diarrhea a day
  • Fatigue due to anemia
  • Severe abdominal pain and cramping
  • A racing heartbeat
  • Fever
  • Weight loss

Some people also develop inflammation outside of the colon. This can cause other symptoms, such as:

  • Swelling and pain in large joints such as the hips and knees
  • Nausea
  • Loss of appetite
  • Itchy eyes
  • Red spots on your skin

Women and ulcerative colitis

Ulcerative colitis symptoms in people assigned female at birth (AFAB) are the same as those in people assigned male at birth (AMAB). However, some people may notice that their symptoms worsen during their period. This may be due to changes in hormones during that time.

Up to sixty percent of people AFAB with inflammatory bowel diseases such as ulcerative colitis also report sexual problems, compared to only about 25 percent of people AMAB with IBD; in some cases, it may be that IBD also affects self-esteem. The symptoms of IBD may also cause sex to be more painful.

The digestive specialists at NewYork-Presbyterian can help treat all of these symptoms and improve your quality of life. Learn about treatment options here.

What Causes Ulcerative Colitis?

What Causes Ulcerative Colitis?

The cause of ulcerative colitis is unknown. However, two main factors may increase the risk of developing UC:

  • Genetics: Ulcerative colitis seems to run in families. If you have a first-degree relative, such as a sibling or parent, with the condition, you may be more at risk. But that only seems to account for 10 to 25 percent of all cases.
  • An overactive immune system: It’s thought that ulcerative colitis could be triggered by a viral or bacterial infection. Your immune system protects you from illness by creating temporary inflammation. But among people with ulcerative colitis, the inflammation continues. As a result, your body keeps sending white blood cells into your gastrointestinal (GI) tract, which causes chronic inflammation and ulcers.

Doctors used to think diet or stress could cause ulcerative colitis. However, research suggests that while both may aggravate the condition, they don’t trigger it.

Risk Factors

Risk Factors

People assigned female at birth and people assigned male at birth are equally affected by ulcerative colitis, although older people AMAB are more likely to be diagnosed than older people AFAB.

There are a few risk factors that may make you more likely to develop the disease. They include:

  • Age: Most people develop ulcerative colitis between the ages of 15 and 30. There may be a second small peak between the ages of 50 and 80.
  • Ethnicity: Ashkenazi Jews are up to four times as likely to develop ulcerative colitis than other people.
  • High-fat diet: Research suggests a diet that is high in animal fat and polyunsaturated fatty acids (found in plant-based oils such as soybean, corn, or sunflower oil) is associated with an increased incidence of ulcerative colitis.
  • Poor sleep: People AFAB who get less than six hours or more than nine hours of sleep a night are at higher risk of developing ulcerative colitis than those who get seven to eight hours.
  • Oral contraceptives: There is a very small increased risk of ulcerative colitis among people who take either the birth control pill or hormone replacement therapy. It’s thought that estrogen may increase the inflammatory response.



Complications of ulcerative colitis include:

  • Anemia: This is due to intestinal bleeding.
  • Bone problems: Many people with ulcerative colitis are treated with medications such as corticosteroids, which may cause bone loss. As a result, they are at greater risk of developing low bone mass or osteoporosis.
  • Delayed growth and development in children: Children with UC may be slow to gain weight or grow and may experience delayed puberty.
  • Increased risk of colon cancer: If your ulcerative colitis involves at least a third of your colon, you’re more likely to develop colon cancer. You’ll, therefore, require more frequent screening.
  • Dehydration: Because UC can cause diarrhea, people with UC have an increased risk of dehydration.
  • Toxic megacolon: Inflammation may spread deep within the large intestine, causing it to swell and stop working.
  • Severe rectal bleeding: This may require emergency surgery.
  • Perforated colon: Rarely, UC can lead to a perforated colon (a hole in the colon), causing stool to leak into the abdomen.
  • Fulminant ulcerative colitis: This is a rare but fairly serious form of UC, which can cause more than 10 bloody bowel movements a day and lead to fever, rapid heart rate, and severe anemia, as well as a higher risk of toxic megacolon — a rare but life-threatening complication that puts the body at risk of infection, dehydration, and shock.
Get Care

Trust NewYork-Presbyterian for Ulcerative Colitis Care

Several ulcerative colitis specialists are at the Jill Roberts Center for Inflammatory Bowel Disease at NewYork-Presbyterian/Weill Cornell Medical Center and the IBD Center at NewYork-Presbyterian/Columbia University Irving Medical Center. We’re proud to provide the latest research-based treatments to relieve symptoms and improve patients' quality of life. Make an appointment with NewYork-Presbyterian today.