What are UC and CD?

Ulcerative colitis (UC) and Crohn’s disease (CD) are types of inflammatory bowel disease (IBD) that are characterised by chronic inflammation of the gastrointestinal (GI) tract.8,9

Ulcerative Colitis

Ulcerative Colitis
  • UC affects only the colon and rectum8
  • Tiny open sores can be seen in this region of the gut using imaging methods8
  • Inflammation is limited to the mucosal layer of the intestine, and causes loss of the colon’s lining8

Crohn's Disease

Crohn's Disease
  • CD can affect the whole length of the GI tract9
  • The most common area affected is the end portion of the small intestine (ileum)9

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Symptoms of UC and CD can vary in degree, depending on the patient and severity of disease.8,9 When the diseases are active, signs and symptoms may include:

  • Abdominal pain
  • Diarrhoea
  • Rectal bleeding
  • Fever
  • Weight loss
  • Signs of malnutrition12

The differentiation between the two conditions may be difficult based on symptoms alone.

Complications of UC can include anaemia and pus production in the GI tract.3 Other complications of UC may include perforated bowel and toxic megacolon,13 which is an acute, non-obstructive dilation of the colon.

Consequences of CD can include perianal disease and abdominal mass.9 Other complications may include bowel obstruction, stricture, perforation, fistula, and abscess.9,13

Both UC and CD can increase the risk of colorectal cancer (CRC):13

  • The risk is related to the duration of the disease
  • Risk is also linked to the extent (i.e. the length of the colon involved) and the severity of the disease

Although much progress has been made in IBD research, a definitive cause has not been found.8,9,13

Several factors may contribute to the risk of developing UC, including:15


Ethnicity: High risk in Caucasians, and notably people of Eastern European (Ashkenazi) Jewish descent


Genetics: Family history – 5–20% of patients have a first-degree relative with IBD13


Habitat: Those living in urban areas and industrial nations may be more likely to develop UC or CD than those in more rural areas

There is no single test to diagnose UC or CD. Diagnosis may involve a combination of the following tests and examinations.8,9

Blood Tests
May be performed to check for anaemia, which may indicate bleeding in the intestines. Blood tests may also uncover a high white blood cell count, which is a sign of inflammation somewhere in the body.8,9

Faecal Tests
By testing a stool (faecal) sample, clinicians can tell if there is bleeding or infection in the intestines. Stool tests are commonly done to rule out other diseases of the GI tract, such as cancer.8,9

Imaging Tests
Magnetic resonance imaging (MRI) or computed tomography (CT) may be used to identify visible abnormalities in the gut.8,9

Flexible sigmoidoscopy and colonoscopy
These tests are performed using a long, flexible tube that has a small video camera on the end. A doctor can carefully examine the rectum and colon for inflammation, bleeding, or ulcers, or may perform a biopsy. The tissue taken during a biopsy can be analysed microscopically to confirm a diagnosis.8,9

The management of IBD may involve medications, surgery, and nutritional support.

The overall aim is to reduce inflammation, correct nutritional deficiencies, and alleviate gastrointestinal symptoms, such as abdominal pain and diarrhoea.8,9


The general categories of drugs used in the treatment of IBD:8,9

  • Aminosalicylates or 5-ASA that reduce gut inflammation
  • Antidiarrhoeal agents that provide symptomatic relief
  • Antibiotics that treat and prevent bacterial infections in the gut
  • Steroids that reduce gut inflammation
  • Immunomodulators that dampen the body’s immune responses that contribute to inflammation in the gut
  • Biologic therapies such as anti-TNFα, anti-integrin and anti-interleukin, that reduce gut inflammation
  • JAK Inhibitors


Surgery may be necessary to relieve symptoms when people do not respond to medications or if complications occur. Removal of specific sections of the small intestine, colon or rectum may be necessary.8,9

Diet and Nutrition

Proper nutrition is also a part of managing both UC and CD, and it is important that patients follow a nutritious diet and avoid foods that may worsen their symptoms.8,9

Reporting of side effects

If you get any side effects, talk to your doctor, pharmacist or nurse. This includes any possible side effects not listed on this website or in the Patient Information Leaflet.

You can also report side effects directly via the Yellow Card Scheme at: www.mhra.gov.uk/yellowcard.

By reporting side effects, you can help provide more information on the safety of this medicine.