Crohn's disease is a long-term condition that causes inflammation of the lining of the digestive system.
Common symptoms can include:

- diarrhoea
- abdominal pain
- fatigue (extreme tiredness)
- unintended weight loss
- blood and mucus in your faeces (stools)

Why it happens

The exact cause of Crohn's disease is unknown. However, research suggests a combination of factors may be responsible. These include:

- genetics – genes you inherit from your parents may increase your risk of developing Crohn's disease
- the immune system – the inflammation may be caused by a problem with the immune system (the body's defence against infection and illness) that causes it to attack healthy bacteria in the gut
- previous infection – a previous infection may trigger an abnormal response from the immune system
- smoking – smokers with Crohn's disease usually have more severe symptoms than non-smokers
- environmental factors – Crohn's disease is most common in westernised countries such as the UK, and least common in poorer parts of the world such as Africa, which suggests the environment (particularly sanitation) has a part to play.

Treating Crohn's disease

There's currently no cure for Crohn's disease, so the aim of treatment is to stop the inflammatory process, relieve symptoms (induce and maintain remission) and avoid surgery wherever possible.

The first treatment offered to reduce symptoms is usually steroid medication (corticosteroids). If this doesn't help, medication to suppress the immune system (immunosuppressants) and medication to reduce inflammation may be used.

In some cases, surgery may be needed to remove the inflamed section of intestine.

Once your symptoms are under control (in remission), further medication may be needed to help maintain this.

(Source: http://www.nhs.uk)