Ulcerative colitis: Get informed

Ulcerative colitis, just as Crohn’s disease, is an inflammatory bowel disease (IBD), but the inflammation is located in the rectum and colon.


ULCERATIVE COLITIS: Definition, symptoms, treatment

What is ulcerative colitis (UC)?


Ulcerative colitis (UC) is one of the 2 major inflammatory bowel diseases (IBD), along with Crohn's disease. It is an autoimmune disease that causes inflammation and ulcers of the inner lining of the rectum, and frequently spreads (unlike Crohn's disease) over part or all of the colon (large intestine):

  • in about 50% of cases, the disease only affects the rectum (this is called proctitis) or extends to the sigmoid colon (this is called proctosigmoiditis);
  • In about 30% of cases, it is an intermediate form of UC with lesions extending to the left or the descending colon (this is called left-sided or distant colitis);
  • In 20% of cases, UC extends from the rectum to the entire colon (known as pancolitis or total colitis).

The disease progresses through periods of flare-ups (painful attacks), interspersed with remissions (the symptoms of the disease reduce), of varying duration and intensity.

How common is ulcerative colitis?

UC is an increasingly common disease, found mainly in the developed countries, with a growing incidence in the developing countries (Asia, Middle East).

It is estimated that about 1 million people are affected with ulcerative colitis in the United States.

It is most often diagnosed in people aged between 30 and 40, but can develop at any age, including children and teenagers. A small incidence peak can also be observed in people aged between 50 and 70.

Men are slightly more affected by this disease, but the difference between the sexes is minimal.

Symptoms and complications of Ulcerative Colitis

The symptoms of ulcerative colitis vary depending on the extent of the digestive lesions during flare-up.

Digestive symptoms

The main symptoms are:

  • Inconsistent diarrhea (4-20 stools per day depending on the extent of the rectocolic lesions);
  • discharge of mucus or blood (rectorrhagia) from the anus
  • false and imperious urges to defecate (colics);
  • rectal and anal pain with sphincter muscle contraction (tenesmus);
    abdominal pain (spasms).

Other common symptoms

Other common symptoms, associated with the digestive symptoms described above, may be observed:

  • severe fatigue (asthenia)
  • weight loss 
  • fever
  • pallor related to anemia due to iron or vitamin B12 deficiency;
  • delayed growth and poor weight gain in children and teenagers.

Non-digestive symptoms

Other parts of the body can also be affected by inflammation, leading to:

  • rheumatic joints: inflammation of the joints of the limbs (knees, ankles, wrists, etc.) or of the spine and pelvis (spondylarthritis);
  • dermatological problems: such as mouth ulcers or erythema nodosum (hard, red and painful blisters on the legs and forearms, which have the size of a walnut);
  • or eye problems such as uveitis (inflammation of the eye: iris, choroid).

Possibles complications

Complications may require urgent treatment or even hospitalization. They include:

  • acute severe colitis which is characterized by bloody stools > 6 times a day, anemia (lack of red blood cells), weight loss and fever. It can lead to an enlarged colon, causing stomach pains and bloating. It increases the risk of perforation of the large intestine and peritonitis (infection of the abdominal cavity), and can also cause significant blood loss (hemorrhage). However, it remains a rare disorder (less than 2% of patients with UC are affected)
  • colon cancer: the risk of developing colon cancer is higher in people with ulcerative colitis. Nevertheless, the risk has reduced with the arrival of new maintenance treatments, but systematic screening for this cancer via a colonoscopy should still be carried out for patients who have been suffering with UC for more than 10 years, especially if the lesions have spread above the sigmoid colon.
  • biliary tract disorders: primary sclerosing cholangitis or PSC (inflammation and thickening of the ducts that carry bile from the liver to the small intestine) can develop in patients with ulcerative colitis. In this case there is an increased risk of developing bile duct or colon cancer.
  • anal fissures: sores in the anus that can develop in people affected with UC.

Ulcerative Colitis causes and risk factors

The causes of ulcerative colitis are still not well known, but various factors (genetic, immunological and environmental) have been identified in the development and aggravation of the symptoms of the disease:

  • genetic predisposition: genes predisposing to UC have been identified, but they only slightly increase the risk of the disease.
  • dysbiosis or changes in the intestinal microbiota (also known as the gut flora, consisting of the bacteria naturally present in the gut): the immune system abnormally attacks the "good" bacteria and leads to inflammation of the intestinal wall, which is observed in UC.
  • given the rapid increase in UC cases in the developed countries, several environmental factors seem to be involved in the development of the disease: stress, diet and pollution are now being studied to prove their involvement in the development of UC.

It is worth mentioning that, paradoxically and contrary to Crohn's disease where it is a triggering factor, active smoking seems to protect against UC .

Furthermore, appendectomy (removal of the appendix) performed before the age of 20 (for appendicitis or inflammation of the appendix) also seems to be a protective factor against UC.

Diagnosing Ulcerative Colitis

The diagnosis of UC is made by a multidisciplinary team (attending physician, gastroenterologist, radiologist, rheumatologist, ophthalmologist, surgeon, pediatrician if the patient is a child, etc.) during an exacerbation.

It is initially based on questioning and examining the patient; UC must be suggested in the event of any prolonged diarrhea associated with hemorrhages (whether or not the patient suffers from abdominal pain) and deterioration of the patient’s general condition.

Complementary examinations to confirm the diagnosis

Various additional examinations are carried out to confirm the diagnosis of UC:

  • rectosigmoidoscopy allows the walls of the rectum, sigmoid colon and left colon to be viewed and assessed. In the case of UC, diffuse lesions with no sites of healthy mucosa are observed. The probe is inserted through the anus after an enema. This examination is performed without anesthesia and does not require an empty stomach.
  • ileocolonoscopy is an examination similar to rectosigmoidoscopy, which allows the upper parts of the intestine to be viewed: the entire colon and the end of the small intestine (ileum). It is performed under general anesthesia or sedation and requires the colon to be emptied of its contents beforehand (the patient can fast, take intestinal lavage preparation before the examination, or even follow a residue-free diet and take laxative medication a few days before the examination).
  • Biopsy (taking samples of small fragments of the intestinal wall) may be performed and samples analyzed to help with the diagnosis.
  • Blood tests allow to look for anemia (decreased red blood cell count), inflammatory syndrome (increased blood levels of C-reactive protein or CRP and ESR), vitamin deficiencies (decreased blood levels of vitamins B12 and D), and assessment of renal (creatinine clearance calculations) and hepatic (elevated blood levels of ASAT and ALAT transaminases, and gamma-GT) damage that may be caused by ulcerative colitis.
  • Bacteriological and parasitological analysis of the stool (coproculture) is used to rule out an infection that may explain the digestive symptoms.

Evaluating the disease activity

Depending on the symptoms, the doctor can assess the severity and the extent of the disease using special scoring tools.

Among the tools used, that of Truelove and Witts makes it possible to identify severe attacks in the context of UC by associating:

  • the number of bowel movements ≥ 6 per day
  • with the presence of at least one of the following signs: profuse rectal bleeding, temperature ≥ 98.6°F, tachycardia ≥ 90 beats per minute, anemia with hemoglobin ≤ 10 g/dL, SV ≥ 30 mm/h or albumin ≤ 35 g/L.

The Montreal classification is derived from the Truelove and Witts index and distinguishes 4 degrees of UC activity (S0: remission, S1 mild activity, S2 moderate activity and S3 severe activity).

It also assesses the extent of the disease by distinguishing between proctitis (E1, limited to the rectum), left-sided colitis (E2, not extending beyond the splenic angle) and extensive colitis (E3, extending beyond the left angle, corresponding to pancolitis).

Treatments for Ulcerative Colitis

Treatments for UC allow to reduce the symptoms, avoid relapses and improve patients’ quality of life.

Drug treatments

A variety of drugs can be used depending on the different manifestations of UC, but they all work to lower the activity of the immune system. These include:

Anti-inflammatory drugs: 

  • Amino-salicylates have an anti-inflammatory action on the intestinal mucosa. Mesalazine or 5-ASA (Pentasa®) is the best tolerated one, but there are also sulfasalazine and olsalazine (Dipentum®). They are effective in treating mild to moderate flare-ups (but are not sufficiently effective in treating severe flare-ups or severe disease) and prevent relapses of UC. They are given rectally as suppositories in the case of proctitis (involvement of the rectum) and as enemas (rectal suspensions) or orally in more extensive forms (involving the colon).
  • Corticosteroids are used during UC attacks. They can be administered orally, such as prednisolone, but also rectally as an enema, such as hydrocortisone, or injected during severe attacks. They are prescribed for short periods of time (maximum 3 months, with a gradual decrease in doses before they are stopped), in order to limit their side effects (high blood pressure, muscle wasting, weight gain, osteoporosis, etc.). When taking them, it is important to have a diet rich in proteins (meat, fish, eggs), low in salt, sugars and fats, and to supplement with calcium and vitamin D.

In addition, people with UC should avoid taking aspirin and non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen. These substances are frequently prescribed to control fever or pain, and can make the symptoms of the disease worse. For the relief of common pains, the use of paracetamol should therefore be preferred.


  • Azathioprine (Imuran®) is prescribed for severe forms of UC in patients who cannot take corticosteroids or in those for whom corticosteroids are insufficiently effective. The effect of azathioprine only becomes apparent after a few weeks or months of treatment. The most common side effects are nausea, blood abnormalities (which require regular blood tests) and an increased risk of infection (the presence of fever requires prompt medical attention).

Biological therapy: 

Biological treatments are treatments with living organisms or substances from living organisms that weaken the body's immune responses and reduce inflammation in the long term. They are prescribed as a second-line treatment for moderate to severe forms of UC in people for whom standard treatment is not effective. Because of the increased risk of infection to which they expose, these medications require a thorough medical check-up (search for latent tuberculosis, dental abscess, ongoing viral infection, etc.) prior to the initiation of treatment and their initial prescription is reserved for hospital specialists.

Biological treatments include anti-TNFα monoclonal antibodies: by binding to TNF (Tumor Necrosis Factor), these drugs block the inflammatory action of this protein. They are administered in injectable form: via infusion for infliximab (Remicade®) or subcutaneously for adalimumab (Humira®) and golimumab (Simponi®). Their biosimilars (with equivalent efficacy and adverse effects to the reference biological drug) are also available.

Two other monoclonal antibodies are indicated for the treatment of adult UC in cases of insufficient response or intolerance to conventional or anti-TNF therapy:

  • vedolizumab (Entyvio®) which blocks a protein on the surface of certain immune cells in the gut. It comes as a powder for injection and is administered as a 30-minute infusion.
  • Ustekinumab (Stelara®), which is an interleukin inhibitor (molecules involved in inflammation). It is an injectable solution, administered subcutaneously.

It should be noted that before starting an immunosuppressive or immunomodulatory treatment, vaccinations must be updated: the pneumococcal vaccine should be received every 5 years and the flu vaccine every year.


Surgery is required in cases of gastrointestinal (GI) bleeding or perforation of the colon. It may also be necessary when medication is insufficient to control the symptoms of UC, or when colon cancer is detected.

Two operations may be performed:

  • a colectomy: the colon is completely removed (the end of the small intestine is sutured to the rectum);
  • a coloprotectomy: the colon and the rectum are removed (the end of the small intestine is sutured to the anal canal and a reservoir is created to replace the rectum).

In some cases, the surgeon cannot suture the healthy parts of the intestine end to end, and thus attaches it to an opening in the abdomen (this is called a stoma). Through this temporary opening, the contents of the intestine are evacuated into a pouch that must be changed regularly. It remains in place until the operated areas have healed and the continuity of the intestine is restored.

Several complications can develop after surgery:

  • Post-operative infection;
  • frequent need to go to the toilet;
  • persistent proctitis (inflammation of the rectum) if the rectum has not been removed;
  • inflammation of the ileal reservoir (pouchitis), created between the small intestine and the anus by the surgeon during suturing
  • occlusion of the small intestine, etc

Living with Ulcerative Colitis

Follow-up care

The attending physician tracks the disease progression and establishes the frequency of follow-up visits. Seeing a hepato-gastroenterologist is recommended once or twice a year when the disease is in remission, and more frequently if it has not stabilized or if it has worsened.

Follow-up care is based on regular clinical examinations, biological analyses (blood tests), regular rectoscopies and colonoscopies. The severity of the disease can be assessed using different scoring tools (mentioned above).

Follow-up visits also provide an opportunity to assess the effectiveness and tolerance of the treatment, as well as the patient's nutritional status.

It should be noted that patients undergoing corticosteroid treatment for more than 6 months should be subject to special monitoring: blood pressure, bone density, measurement of blood glucose (sugar) levels, eye examination, etc.

Well-balanced diet

Food does not trigger the inflammation of the intestine, but it can temporarily accentuate the symptoms. A balanced and varied diet is preferable in order to avoid any deficiency. And a supplementation in minerals (calcium, iron...) and vitamins (vitamin D, vitamin C...) may be necessary.

During flare-ups, a low-fiber diet (limited in fruit and vegetables) may be recommended to avoid accentuating digestive symptoms (diarrhea, pain, bloating).


UC does not affect fertility. However, its flare-ups can cause miscarriages, and in the case of complete removal of the colon and rectum with ileoanal anastomosis, there is a risk of infertility.

After consulting with your attending physician, it is advisable to plan your pregnancy once UC is in remission, as the risk of relapse during pregnancy is lower in this case.

Finally, most of the drugs prescribed as maintenance treatment for UC are compatible with pregnancy.

Social life

UC does not interfere with normal schooling, sports and professional life.

In addition, patient education programs are becoming more and more common in hospitals. These are individual or group sessions that provide patients with personalized information in order to understand and master their care pathway (understanding the disease, treatments, sharing difficulties and improving daily life, etc.).

Finally, patients can benefit from psychological support, and contact patient organizations to learn more about their disease, meet other patients, etc.

There is, for example Crohn's and Colitis Foundation, non-profit organization which has been funding research studies and clinical trials in IBD since 1967. It also helps patients and caregivers find information about their disease and receive all the support they need. Moreover, the organization educates healthcare professionals and publishes 2 scientific journals.

In conclusion, ulcerative colitis is one of the main chronic inflammatory bowel diseases (along with Crohn's disease), the exact causes of which are still unknown. Moreover, there is no cure for the disease, but the current medications usually allow for a long-lasting control of the symptoms and a satisfactory quality of life outside flare-ups.

avatar Alexandre Moreau

Author: Alexandre Moreau, Digital Marketing Assistant

Within the Digital Marketing team, Alexandre is in charge of writing medical factsheets and scientific articles. He is also in charge of leading and moderating the community on the forum, in order to ensure optimal... >> Learn more

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