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Ulcerative Colitis

In this section, you or a loved one can find out more about medical treatments, research studies and practical information about ulcerative colitis (UC). Read on to find answers to some of your questions as well as links to other information. Being informed is an important first step towards becoming an active decision-maker in your care plan.

What Is Ulcerative Colitis?

Ulcerative colitis (UC) is an inflammatory bowel disease that causes inflammation and ulcers in your digestive tract. It affects the innermost lining of your colon and rectum. Many people find UC debilitating and it can sometimes lead to life-threatening complications. It is one of the two most common conditions associated with inflammatory bowel disease, the other being Crohn's disease (CD).

These two conditions should not be confused with irritable bowel syndrome (IBS; also called "spastic colon" or "nervous colitis"), which is a disorder that affects the muscle contractions of the colon. Irritable bowel syndrome does not involve intestinal inflammation and is a much less serious disease than CD or UC. But the symptoms are very similar, which often leads to misdiagnosis.

There are four main types of UC:

  • Ulcerative proctitis: About 30 percent of all cases of UC begin as ulcerative proctitis, which is limited to the rectum. Because it affects a relatively small part of the gastrointestinal tract, this form of the disease is relatively mild, with fewer complications and a more positive disease outlook (prognosis).
  • Proctosigmoiditis: This form of UC affects the rectum and sigmoid colon, which is the segment of colon directly above the rectum. Proctosigmoiditis is often associated with a constant feeling of needing to pass stool (tenesmus) as well as pain in the lower left side of the abdomen.
  • Left-Sided Colitis: This form of the disease involves inflammation that extends from the rectum to the splenic flexure, which is a bend in the colon near the spleen. Left-sided colitis is often associated with loss of appetite, weight loss, diarrhoea, severe pain on the left side of the abdomen and bleeding.
  • Pan-ulcerative Colitis: This condition affects the entire colon and is also known as total colitis. Symptoms may consist of diarrhoea, severe pain, cramps, bleeding and major weight loss. An uncommon complication, toxic megacolon, may develop, which may result in the bowel wall rupturing. Bowel wall ruptures lead to serious complications and often require surgery.
What Causes Ulcerative Colitis?

Scientists do not yet know what causes ulcerative colitis (UC). They suspect that UC inflammation may be caused by a combination of an overactive immune system, environmental factors, the microbiome (bacteria in the colon) and a person's own genetics. It is not clear what the direct cause of the inflammation is or what causes some people's immune systems to "go into overdrive" trying to protect the body. One way the immune system tries to protect the body is through inflammation, and the immune systems of people with UC seem to produce over-reactive, poorly controlled inflammation in the GI tract. Scientists believe that once the UC patient's immune system is "turned on", it does not know how to properly "turn off". As a result, inflammation damages the bowel and causes UC symptoms. This failure of the immune system to "turn off" is why the main goal of medical therapy for UC is to help patients regulate their immune system. 

Scientists suspect that genes may play a role. It is not yet completely understood how or why certain genes or changes in genes are associated with UC, but it is a major focus of current research. People who have a parent, sibling or child with UC have a much higher risk of developing it themselves.
Normally, the immune cells protect the body from infection. In people with UC, however, the immune system mistakes food, non-harmful bacteria and other things that are supposed to be in the bowel for substances that pose a threat. In response, it attacks the bowel lining and produces chronic inflammation. This inflammatory reaction continues without proper control, which then damages the bowel wall. When the bowel wall is damaged, UC symptoms occur, such as diarrhoea and abdominal pain.

Risk factors are personal characteristics that are known to be associated with a greater likelihood of having a disease or condition. But these risk factors, such as age or where you live, do not necessarily cause UC. Also, absence of a risk factor may not mean protection from UC.

Risk factors may include:

  • Age: There is good evidence that the younger you develop the disease, the more aggressive it will be. It is also thought that if you develop the disease early in life, genetics are likely playing an important causative role. If disease onset is later in life, it is thought to be more due to environmental factors.
  • Isotretinoin acne medication use: Isotretinoin is an oral medication (Accutane) sometimes used to treat scarring acne that does not respond to other treatments. There is conflicting information as to whether isotretinoin use alone or in combination with antibiotics can increase the risk of UC. Some studies have suggested a possible link, while other studies have found no such evidence.
  • Some pain relievers: Ibuprofen, naproxen and Aspirin have been shown to cause sores in the lining of the GI tract (gastrointestinal ulceration) and may make UC worse. Paracetamol poses a much lower risk. Discuss the use of any pain medication with your doctor.
  • Appendix: Although there is conflicting data, some research suggests that removal of the appendix (appendicectomy) may be protective to developing UC.
What Are the Symptoms of Ulcerative Colitis?

People with ulcerative colitis (UC) suffer a wide range of symptoms, most of them mild to moderate, depending on which part of the colon is affected. The disease is usually relapsing and remitting, which means that there can be periods of disease flare-up (active disease) and remission (temporary end to the medical signs and symptoms). 

Common symptoms include:

  • Abdominal pain and cramping
  • Diarrhoea, often with blood or pus
  • Difficulties with defecation, despite a feeling of urgency
  • Failure to grow (in children)
  • Fatigue
  • Fever
  • Loss of appetite
  • Rectal bleeding or pain
  • Weight loss
Are There Other Complications

The severity of ulcerative colitis (UC) symptoms can differ widely from person to person and depends on many factors, including how much of the colon is affected. The digestive system is the part of the body that is affected most directly, but complications can potentially affect other parts of the body as well.

  • Fulminant colitis: Causes damage to the intestinal wall (as well as dilation and swelling of the colon) and affects fewer than 10 percent of ulcerative colitis (UC) patients. The dilation and swelling of the colon can lead to another condition called ileus, which is a functional blockage of the intestines caused by a lack of peristalsis. Peristalsis is the pumping action of the intestines that helps to move food through the digestive system.
  • Severe bleeding: May result in low red blood cell levels (anaemia) or extreme blood loss (haemorrhaging).
  • Perforated colon: If the inflammation and ulcers in the colon are severe, the wall of the colon may rupture, which is known as a perforation. A perforated colon may be associated with toxic megacolon. A perforation may allow bacteria to enter the body and cause an infection. A perforated colon requires immediate intervention and often requires surgery.
  • Increased risk of colon cancer: People with UC should be screened more often.
  • Toxic megacolon: Part of the large intestine stops working and swells to a large size. This is a dangerous complication that requires medical attention and sometimes requires surgery. 

Ulcerative colitis is a systemic disease, which means that it can affect the entire body. The complications that occur outside of the GI tract are called extra-intestinal manifestations. Although more common in Crohn's disease, patients with UC an also have these complications.

Some of the common complications are:

  • Primary sclerosing cholangitis (PSC): a rare complication associated with UC that results in chronic liver disease
  • Other liver diseases: fatty liver, chronic active hepatitis,  amyloidosis
  • Skin manifestations: erythema nodosum (raised, tender, red nodules appearing typically on the limbs), pyoderma gangrenosum (rare ulcerating lesion)
  • Arthritis and arthralgias
  • Eye inflammation
  • Osteoporosis
Lifestyle Options

For most people, regardless of having ulcerative colitis (UC) or not, exercise, healthy eating and good sleep habits are recommended. A healthy lifestyle can lead to an enhanced quality of life for most people. Talk to your doctor before making any lifestyle changes. 

While diet is not thought to cause UC, people experiencing symptoms of the disease often find some foods aggravating. It may be helpful to keep (and regularly review) a food diary to better understand how your body is reacting to various foods. Many people find soft, bland foods make them feel better than spicy ones. Several small meals may work better then two or three large ones. If you are lactose intolerant, you may want to avoid dairy products.

In addition, chronic diseases like UC tend to increase the body's energy needs. Since UC can cause a loss of appetite, staying nourished make take extra effort. In general, it is best to maintain a high-quality, well-balanced diet with ample fluids. Working with a registered dietitian may be beneficial.

Even light exercise, especially when done regularly, can help reduce stress, improve mood and normalise bowel function.
Complementary Therapy Options

Vitamins and probiotics: As long as their own doctors agree, people with ulcerative colitis (UC) may benefit from vitamin supplements as well as the introduction of "good" bacteria into the intestine.

Mind-body medicine: People with UC may want to manage stress by using methods that focus on the connection between emotions, the body and individual health. Examples include tai chi, biofeedback, hypnosis, yoga and meditation.

Medical Treatment


The goals of medical treatment for UC are :

  • Absence of symptoms (achieving remission)
  • Preventing flare-ups of disease (maintaining remission)
  • Improving personal quality of life
  • Healing the gut

The goal of treating UC is to decrease or stop the inflammation. The type of medication that is prescribed depends on the severity of the disease. Common medications that can decrease inflammation are corticosteroids, immunomodulators (e.g. azathioprine, methotrexate, 6- mercaptopurine) and drugs known as biologics, which target specific pathways believed to be involved in the disease. 

Other medications may include:

  • Antibiotics to prevent or control infection
  • Aminosalicylates
  • Anti-diarrheal medications
  • Pain relievers including paracetamol
  • Iron supplements to control anaemia
Surgery may eliminate ulcerative colitis (UC), but it may require removing the entire colon (colectomy) or, in a procedure called a proctocolectomy, removing the colon and rectum (i.e. the large bowel). In most cases, this is accompanied by a procedure called an ileoanal anastomosis, which is a procedure where the surgeon uses the end of your small intestine to create a pouch that is attached directly the anus. Because the muscles of the anus are left in place, bowel movements remain relatively normal.
Because ulcerative colitis (UC) carries a higher risk of colon cancer, your doctors may recommend more frequent colonoscopies. A gastroenterologist will recommend the frequency of screening, which depends on the age of the patient, location and duration of the disease, as well as other risk factors.

Please note that the information on this website is intended for informational purposes only and should not be used as a substitute for seeking medical advice or treatment from a healthcare professional. You should not use this information to diagnose or treat a medical condition or health problem. Speak to a healthcare professional if you have any questions about your health, medical condition, symptoms or treatment options.


UK charity for Crohn’s Disease and Ulcerative Colitis.

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