Understanding Crohn’s Disease

For more information about Crohn’s disease (CD) and its treatment please select from the options below:

Crohn’s disease (CD) is a type of inflammatory bowel disease (IBD) that is characterised by chronic inflammation of the gastrointestinal (GI) tract.1-3

  • Unlike ulcerative colitis (UC), CD can affect the whole length of the gastrointestinal tract1-3
  • The most common area affected is the end portion of the small intestine (ileum)1-3

Symptoms of CD can vary in degree, depending on the individual and severity of disease.1,2 When the disease is active, signs and symptoms may include:

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

Crohn’s disease and ulcerative colitis share many of these symptoms,1,2 so it can be difficult for doctors to distinguish between these two inflammatory bowel diseases.

Consequences of CD can include intestinal blockage caused by swelling and scar tissue on the intestinal wall. CD may also cause ulcers that tunnel through the affected area. These are called fistulas. Abcesses are also a common complication.2,3

Both UC and CD can increase the risk of colorectal cancer (CRC):3

  • 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.2,3

Several factors may contribute to the risk of developing IBD, including:2,3


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 IBD


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

Diagnosis may involve a combination of the following tests and examinations.1,2

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.1,2

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.1,2

Imaging Tests
Magnetic resonance imaging (MRI) or computed tomography (CT) may be used to examine the small intestine in people with suspected Crohn’s disease in order to identify visible abnormalities in the gut.1,2

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, colon and small intestine for inflammation, bleeding, or ulcers, or may perform a biopsy. The tissue taken during a biopsy can be analysed microscopically to confirm a diagnosis.1,2

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.1,2


The general categories of drugs used in the treatment of CD:1,2

  • Antibiotics that commonly treat and prevent bacterial
  • Steroids that reduce gut inflammationinfections in the gut
  • 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


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.1-3

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.2

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.