What is Crohn’s disease?

Crohn’s disease is a chronic, lifelong condition which is part of a group of conditions known as inflammatory bowel disease (IBD). It causes inflammation of the gastrointestinal tract (gut).

Crohn's disease - so what is it?

Crohn’s disease is a chronic, lifelong condition which is part of a group of conditions known as inflammatory bowel disease (IBD). It causes inflammation of the gastrointestinal tract (gut). This inflammation can be anywhere from the mouth to the anus and most commonly affects the end of the small bowel (the ileum) and the beginning of the colon.

Crohn’s disease is named after Dr Burrill B. Crohn, who first described the disease in 1932 along with colleagues Dr. Leon Ginzburg and Dr, Gordon D. Oppenheimer.

The other main type of IBD is ulcerative colitis (UC). Crohn’s disease and UC share some of the same symptoms, but it is important to understand that they affect different areas of the gut.

While Crohn’s disease can affect any of the gastrointestinal tract (GI tract) UC just affects the colon (large intestine) and rectum. Crohn’s disease can also affect the entire thickness of the digestive tract wall, while UC only involves the innermost lining of the colon. Crohn’s disease may also skip areas - meaning you could have inflammation near you mouth and also in your small bowel but no where in between.

It is thought to be an autoimmune condition.

There is no known cure for Crohn’s disease. Some people have surgery to remove parts of their gut which are affected but inflammation could return at another time and having this surgery doesn’t necessarily remove all of the symptoms of IBD.


What are the symptoms of Crohn’s disease?

Crohn's disease symptoms vary greatly depending on where you have inflammation.

Some of the common symptoms of Crohn’s disease include:

  • Diarrhoea which may be mixed with mucus, blood or pus
  • Urgency to go to the toilet
  • Abdominal cramps and pain
  • Constipation
  • Tiredness and fatigue
  • Feeling generally unwell
  • Loss of appetite
  • Unintended weight loss
You may experience just one or a number of the symptoms above. Some of the other Crohn's disease symptoms include:
  • A high temperature (fever) of 38C (100F) or above
  • Feeling sick (nausea)
  • Being sick (vomiting)
  • Joint pain and swelling
  • Inflammation and irritation of the eyes
  • Areas of painful, red and swollen skin ‐ most often the legs
  • Mouth ulcers
Inflammation can prevent the body from absorbing nutrients. This can mean that children with Crohn’s disease grow at a slower rate than expected.

What are the different types of Crohn’s disease?

Depending on where you have inflammation will depend on the type of Crohn’s disease you have. The types of Crohn’s disease are:

How is Crohn’s disease diagnosed?

There is no one method of diagnosing Crohn’s disease. If you have been suffering from Crohn’s-type symptoms for several weeks or more then the following tests may be carried out:

How do you treat Crohn’s disease?

Unfortunately there is no known cure for Crohn’s disease.

The main methods of treating Crohn's disease used by healthcare are:

Some people also make changes in their lifestyle to help manage some of the life-affecting symptoms of the condition.

These include:

What causes Crohn’s disease?

No one really knows what the exact cause of Crohn’s disease is. The cause is often put down to a number of factors including:

  • Genetics
  • A problem with the immune system in which it attacks healthy bacteria in the gut
  • A previous infection which has triggered an abnormal response from the immune system
  • Smoking
  • Environmental factors
Scientists continue to carry out research into the causes.

Learn more about the causes of Crohn's disease

Who gets Crohn’s disease?

There are millions of people around the world who suffer from Crohn’s disease so it’s important to remember that you are not alone. It can affect people of all ages, including children, however it most commonly first develops between the ages of 16 - 30. A large number of cases also develop between 60 - 80.

What is remission?

People with Crohn’s disease often go through periods of flare-ups where they have severe symptoms and periods where their symptoms are more mild or non-existent. Someone with the disease who isn’t displaying any symptoms is known to be in remission.

What are the complications of Crohn’s disease?

Over time there are various complications that can occur as a result of Crohn’s disease. These include:

  • Strictures - narrowing of the intestine caused by inflammation
  • Fistulas - a channel developing between the end of the bowel and the skin near the anus or vagina
  • Osteoporosis - weakening of the bones
  • Deficiencies in iron, vitamin B12, folate and other vitamins and minerals
  • Pyoderma gangrenosum - a rare skin reaction that causes skin ulcers
  • Slow growth in children
  • Slightly increased risk of developing colorectal cancer in later life

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