Crohn's Disease

What is Crohn's Disease?

Crohn’s disease is a type of inflammatory bowel disease that can affect any part of your gastrointestinal tract, however most commonly affects the end of your small intestine and beginning of your large intestine. It causes inflammation (redness and swelling) along the lining of the intestine which can then lead to small sores, or ulcers, to form. The inflammation can affect the entire thickness of the bowel wall, and can ‘skip’, or leave normal areas in between patches of inflamed intestine.

What causes Crohn’s disease?

The exact cause is unclear, however there are a variety of factors that may play a role in causing Crohn’s disease. These factors include genetics, environmental factors (including smoking) and an abnormal immune response by the body.

Who is affected?

Crohn’s disease can occur at any age, however it is typically diagnosed in late teenagers and young adults. There is an increased risk of developing the disease if you have a family member with this condition.

Common symptoms

The most common symptoms include diarrhoea, blood in your stool, abdominal pain, fatigue, malnutrition and weight loss. The range of symptoms can be mild to debilitating.

What are the possible complications of Crohn’s disease?

Possible complications may include the following:

Obstruction in the intestines

The inflammation in Crohn’s disease can affect the entire thickness of the intestine. Over time, these regions of thickening can cause narrowing of the intestine, which can then cause a blockage. This can stop food from passing through the intestines, causing abdominal pain and vomiting.


The inflammation can go through the wall of the intestines, causing abnormal passages between the intestines and other areas of the body (e.g. the skin). These passages can become infected.


The inflammation in the intestines can stop them from absorbing vitamins, minerals and nutrients. This can cause weight loss.

How is Crohn's Disease diagnosed?

Blood tests are performed initially to assess whether any markers of inflammation are high or if you are anaemic. Stool samples are also collected. Imaging tests such as an MRI scan are useful to assess for inflammation in your small intestine. A colonoscopy is usually required to visualise the lining of the large intestine and end of the small intestine, and for biopsies to be taken so a pathologist can examine it under a microscope to look for signs of the disease.

How do you treat the disease?

Unfortunately there is no cure for Crohn’s disease. However there are a variety of medications available that are used to reduce the level of inflammation in the gastrointestinal tract. Sometimes, surgery is required to remove damaged portions of the gastrointestinal tract. The goals of treatment are to:
a) control the inflammation and get you ‘in remission’,
b) keep you ‘in remission’ long-term, and
c) improve your quality of life by controlling your symptoms.

What should I do if I think I have Crohn’s disease?

You should first see your general practitioner. A medical history and examination should be performed, and simple tests may occur initially. You may then be referred to a gastroenterologist to review the history and test results, and if required, a colonoscopy or further imaging tests will then occur to confirm the diagnosis.

Further Information

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