All About Ulcerative Colitis

Definition & Facts  

What is ulcerative colitis? 

Ulcerative colitis is a chronic disease in which abnormal reactions of the immune system cause inflammation and ulcers on the inner lining of your large intestine. 

Ulcerative colitis can begin gradually and become worse over time. However, it can also start suddenly. Symptoms can range from mild to severe. In between periods of flares (when people have symptoms or more severe symptoms) most people have periods of remission (when symptoms lessen or disappear).  

Periods of remission can last for weeks or years. The goal of treatment is to keep people in remission long term. 

Does ulcerative colitis have another name? 

Ulcerative colitis is an inflammatory bowel disease (IBD). Crohn’s disease and microscopic colitis are other common types of IBD. 

How common is ulcerative colitis? 

Research suggests that about 600,000 to 900,000 people (about half the population of Idaho) in the United States have ulcerative colitis. 

Who is more likely to have ulcerative colitis? 

Ulcerative colitis is more likely to develop in people: 

  • Between the ages of 15 and 30, although the disease may develop in people of any age 
  • Who have a first-degree relative — a parent, sibling, or child — with IBD 
  • Of Jewish descent 

What are the complications of ulcerative colitis? 

Ulcerative colitis may lead to complications that develop over time, such as: 

  • Anemia, a condition in which you have fewer red blood cells than normal. Ulcerative colitis may lead to more than one type of anemia, including iron-deficiency anemia and anemia of inflammation or chronic disease. 
  • Bone problems because ulcerative colitis and corticosteroids used to treat the disease can affect the bones. Bone problems include low bone mass, such as osteopenia or osteoporosis. 
  • Problems with growth and development in children, such as gaining less weight than normal, slowed growth, short stature, or delayed puberty. 
  • Colorectal cancer, because patients with long-standing ulcerative colitis that involves a third or more of the colon are at increased risk and require closer screening. 

In some cases, ulcerative colitis may lead to serious complications that develop quickly and can be life-threatening. These complications require treatment at a hospital or emergency surgery.  

Serious complications include: 

  • Fulminant ulcerative colitis, which causes extremely severe symptoms, such as more than 10 bloody bowel movements in a day, often with fever, rapid heart rate, and severe anemia. People with fulminant ulcerative colitis have a higher chance of developing other complications, such as toxic megacolon and perforation. 
  • Perforation, or a hole in the wall of the large intestine. 
  • Severe rectal bleeding or passing a lot of blood from the rectum. In some cases, people with ulcerative colitis may have severe or heavy rectal bleeding that may require emergency surgery. 
  • Toxic megacolon, which occurs when inflammation spreads to the deep tissue layers of the large intestine, and the large intestine swells and stops working. 

Severe ulcerative colitis or serious complications may lead to additional problems, such as severe anemia and dehydration. These problems may require treatment at a hospital with blood transfusions or intravenous (IV) fluids and electrolytes. 

Health problems affecting other parts of the body 

Some people with ulcerative colitis also have inflammation in parts of the body other than the large intestine, including the: 

  • Joints, causing certain types of arthritis  
  • Skin 
  • Eyes 
  • Liver and bile ducts, causing conditions such as primary sclerosing cholangitis 

People with ulcerative colitis also have a higher risk of blood clots in their blood vessels. 

Colorectal cancer 

Ulcerative colitis increases the chance of getting colorectal cancer. People have a higher risk for developing colorectal cancer if ulcerative colitis affects more of their large intestine, is more severe, started at a younger age, or has been present for a longer time.  

People with ulcerative colitis also have a higher risk of developing colorectal cancer if they have primary sclerosing cholangitis or have a family history of colorectal cancer. 

If you have ulcerative colitis, your doctor may recommend a colonoscopy to screen for colorectal cancer. Screening is testing for diseases when you have no symptoms. Screening can check for dysplasia — precancerous cells — or colorectal cancer. Diagnosing cancer early can improve chances for recovery. 

For people with ulcerative colitis, doctors typically recommend colonoscopies every 1 to 3 years, starting 8 years after ulcerative colitis started. For people with ulcerative colitis and primary biliary cholangitis, doctors typically recommend colonoscopies every year, starting at diagnosis. 

Symptoms & Causes of Ulcerative Colitis 

What are the symptoms of ulcerative colitis? 

Symptoms of ulcerative colitis vary from person to person. Common symptoms of ulcerative colitis include: 

  • Diarrhea 
  • Passing blood with your stool or rectal bleeding 
  • Cramping and pain in the abdomen 
  • Passing mucus or pus with your stool 
  • Tenesmus, which means feeling a constant urge to have a bowel movement even though your bowel may be empty 
  • An urgent need to have a bowel movement 

Symptoms of ulcerative colitis may vary in severity.  

Mild symptoms may include having fewer than four bowel movements a day and sometimes passing blood with stool. 

Severe symptoms may include having more than six bowel movements a day and passing blood with stool most of the time.  

Extremely severe — or fulminant — ulcerative colitis, you may have more than 10 bloody bowel movements in a day. 

Some symptoms are more likely to occur if ulcerative colitis is more severe or affects more of the large intestine. These symptoms include: 

  • Fatigue, or feeling tired 
  • Fever 
  • Nausea or vomiting 
  • Weight loss 

You may have periods of remission — times when symptoms disappear — that can last for weeks or years. After a period of remission, you may have a relapse or a return of symptoms. 

What causes ulcerative colitis? 

Doctors aren’t sure what causes ulcerative colitis. Experts think that the following factors may play a role in causing ulcerative colitis. 


Ulcerative colitis sometimes runs in families. Research suggests that certain genes increase the chance that a person will develop ulcerative colitis. 

Abnormal immune reactions 

Abnormal reactions of the immune system may play a role in causing ulcerative colitis. Abnormal immune reactions lead to inflammation in the large intestine. 


The microbes in your digestive tract — including bacteria, viruses, and fungi — that help with digestion are called the microbiome. Studies have found differences between the microbiomes of people who have IBD and those who don’t. Researchers are still studying the relationship between the microbiome and IBD. 


Experts think a person’s environment — one’s surroundings and factors outside the body — may play a role in causing ulcerative colitis. Researchers are still studying how people’s environments interact with genes, the immune system, and the microbiome to affect the chance of developing ulcerative colitis. 

Diagnosis of Ulcerative Colitis 

How do doctors diagnose ulcerative colitis? 

To diagnose ulcerative colitis, doctors review medical and family history, perform a physical exam, and order medical tests. Doctors order tests to: 

  • Confirm the diagnosis of ulcerative colitis 
  • Find out how severe ulcerative colitis is and how much of the large intestine is affected 
  • Rule out other health problems — such as infections, irritable bowel syndrome, or Crohn’s disease — that may cause symptoms like those of ulcerative colitis. 

Medical and family history 

To help diagnose ulcerative colitis, your doctor will ask about your symptoms, your medical history, and any medicines you take. Your doctor will also ask about lifestyle factors, such as smoking, and about your family medical history. 

Physical exam 

During a physical exam, your doctor may 

  • Check your blood pressure, heart rate, and temperature. If you have ulcerative colitis, doctors may use these measures, along with information about your symptoms and test results, to find out how severe the disease is. 
  • Use a stethoscope to listen to sounds within your abdomen 
  • Press on your abdomen to feel for tenderness or masses 

The physical exam may also include a digital rectal exam to check for blood in your stool. 

What tests do doctors use to diagnose ulcerative colitis? 

Doctors may use blood tests, stool tests, and endoscopy of the large intestine to diagnose ulcerative colitis. 

Blood tests 

A health care professional will take a blood sample from you and send the sample to a lab. Doctors use blood tests to check for signs of ulcerative colitis and complications, such as anemia. Blood tests can also show signs of infection or other digestive diseases. 

Stool tests 

A health care professional will give you a container for catching and storing the stool. You will receive instructions on where to send or take the container for analysis. Doctors may use stool tests to check for conditions other than ulcerative colitis, such as infections that could be causing your symptoms. Doctors may also use stool tests to check for signs of inflammation in the intestines. 

Endoscopy of the large intestine 

Doctors order endoscopy of the large intestine with biopsies to diagnose ulcerative colitis and rule out other digestive conditions. Doctors also use endoscopy to find out how severe ulcerative colitis is and how much of the large intestine is affected. 

During an endoscopy, doctors use an endoscope — a long, flexible, narrow tube with a light and a tiny camera on one end — to view the lining of the large intestine. Doctors obtain biopsies by passing an instrument through the endoscope to take small pieces of tissue from the lining of your rectum and colon. A pathologist will examine the tissue under a microscope. 

Two types of endoscopies used to diagnose ulcerative colitis are: 

  • Colonoscopy, in which a doctor uses a type of endoscope called a colonoscope to view the lining of your rectum and your entire colon 
  • Flexible sigmoidoscopy, in which a doctor uses a type of endoscope called a sigmoidoscope to view the lining of your rectum and lower colon 

Treatment for Ulcerative Colitis 

How do doctors treat ulcerative colitis? 

Doctors treat ulcerative colitis with medicines and surgery. Each person experiences ulcerative colitis differently, and doctors recommend treatments based on how severe ulcerative colitis is and how much of the large intestine is affected. Doctors most often treat severe and fulminant ulcerative colitis in a hospital. At present, there is no known cure for ulcerative colitis.


Doctors prescribe medicines to reduce inflammation in the large intestine and to help bring on and maintain remission — a time when your symptoms disappear. People with ulcerative colitis typically need lifelong treatment with medicines unless they have surgery to remove the colon and rectum. 

Which medicines your doctor prescribes will depend on how severe ulcerative colitis is. Ulcerative colitis medicines that reduce inflammation in the large intestine include: 

  • Aminosalicylates, which doctors prescribe to treat mild or moderate ulcerative colitis or to help people stay in remission. 
  • Corticosteroids also called steroids, which doctors prescribe to treat moderate to severe ulcerative colitis and to treat mild to moderate ulcerative colitis in people who don’t respond to aminosalicylates. Doctors typically don’t prescribe corticosteroids for long-term use or to maintain remission. Long-term use may cause serious side effects. 
  • Immunosuppressants, which doctors may prescribe to treat people with moderate to severe ulcerative colitis and help them stay in remission. Doctors may also prescribe immunosuppressants to treat severe ulcerative colitis in people who are hospitalized and don’t respond to other medicines. 
  • Biologics, which doctors prescribe to treat people with moderate to severe ulcerative colitis and help them stay in remission. 
  • A novel small molecule medicine, which doctors may prescribe for adults with moderate to severe ulcerative colitis who don’t respond to other medicines or who have severe side effects with other medicines. 


Your doctor may recommend surgery if you have: 

  • Colorectal cancer  
  • Dysplasia, or precancerous cells that increase the risk for developing colorectal cancer 
  • Complications that are life-threatening, such as severe rectal bleeding, toxic megacolon, or perforation of the large intestine 
  • Symptoms that don’t improve or stop after treatment with medicines 
  • Symptoms that only improve with continuous treatment with corticosteroids, which may cause serious side effects when used for a long time 

To treat ulcerative colitis, surgeons typically remove the colon and rectum and change how your body stores and passes stool. The most common types of surgery for ulcerative colitis are: 

  • Ileoanal reservoir surgery. Surgeons create an internal reservoir, or pouch, from the end part of the small intestine, called the ileum. Surgeons attach the pouch to the anus. Ileoanal reservoir surgery most often requires two or three operations. After the operations, the stool will collect in the internal pouch and pass through the anus during bowel movements. 
  • Ileostomy. Surgeons attach the end of your ileum to an opening in your abdomen called a stoma. After an ileostomy, the stool will pass through the stoma. You’ll use an ostomy pouch — a bag attached to the stoma and worn outside the body — to collect stool. 

Surgery may be laparoscopic or open. 

  • Laparoscopic surgery. Surgeons make small cuts in your abdomen and insert special tools to view, remove, or repair organs and tissues. 
  • Open surgery. Surgeons make a larger cut to open your abdomen. 

If you are considering surgery to treat ulcerative colitis, talk with your doctor or surgeon about what type of surgery might be right for you and the possible risks and benefits. 

How do doctors treat symptoms and complications of ulcerative colitis? 

Doctors may recommend or prescribe other treatments for symptoms or complications of ulcerative colitis. Talk with your doctor before taking any over-the-counter medicines. 

To treat mild pain, doctors may recommend acetaminophen instead of nonsteroidal anti-inflammatory drugs (NSAIDs). People with ulcerative colitis should avoid taking NSAIDs for pain because these medicines can make symptoms worse. 

To prevent or slow loss of bone mass and osteoporosis, doctors may recommend calcium and vitamin D supplements or medicines, if needed. For safety reasons, talk with your doctor before using dietary supplements or any other complementary or alternative medicines or practices. 

Doctors most often treat severe complications in a hospital. Doctors may give: 

  • Antibiotics, if severe ulcerative colitis or complications lead to infection 
  • Blood transfusions to treat severe anemia 
  • IV fluids and electrolytes to prevent and treat dehydration 

Doctors may treat life-threatening complications with surgery. 

Eating, Diet, & Nutrition for Ulcerative Colitis 

What should I eat if I have ulcerative colitis? 

If you have ulcerative colitis, you should eat a healthy, well-balanced diet. Talk with your doctor or Trellus Health Care Team about a healthy eating plan. 

Ulcerative colitis symptoms may cause some people to lose their appetite and eat less, and they may not get enough nutrients. In children, a lack of nutrients may play a role in problems with growth and development. 

Researchers have not found that specific foods cause ulcerative colitis symptoms, although healthier diets appear to be associated with less risk of developing IBD. Researchers have not found that specific foods worsen ulcerative colitis. Talk with your doctor or Care Team about any foods that seem to be related to your symptoms. Your doctor may suggest keeping a food diary to help identify foods that seem to make your symptoms worse. 

Depending on your symptoms and the medicines you take, your doctor or Care Team may recommend changes to your diet. They may also recommend dietary supplements. 

Source: National Institute of Diabetes and Digestive and Kidney Diseases