Your chances of getting the disease increase with age, especially after 55 years. It is most common in people over 70. However, younger people can also get it.

We don't know exactly what causes most bowel cancers, but studies show you are more at risk if:

• You eat a diet high in animal fats (but oily fish is good) and low in fruit and vegetables, especially when this is combined with lack of exercise.
  
   
• You have had an inflammatory bowel disease (colitis) for a long time. Most people who have this increased risk are checked regularly by their specialist.
  
   
• You have polyps in your bowel. A polyp is a non-cancerous growth but some may turn cancerous.
  
   
• You have inherited a genetic abnormality. Around one in twenty patients with bowel cancer has inherited a change in their genes that increases their chance of developing bowel cancer. Most families with this risk know about the problem.

  You may be in this group if you have:

  – one or more close relative (parent, brother, sister, half-sister, half-brother) who has developed the disease before the age of 45, or
  
  – three or more other blood relatives of different generations (such as your grandparents, aunts and uncles, and cousins) who have developed the disease before the age of 50.
  
   

• You have had radiotherapy a long time ago for cancer of the neck of the womb (cervix) – this is rare.

Having one or more of these risk factors does not mean that you will develop colorectal cancer. It just increases the possibility. If you are concerned about your risk, speak to your GP about it.