The exact cause of colorectal cancer is as yet unknown however there are certain factors that can put people at risk:-

Family History

Colorectal cancer can occur in a number of people who have significant family history of the disease. Around 5% of colorectal cancers are thought to be caused by an inherited predisposition.

Familial Adenomatous Polyposis Coli (FAP) is an inherited condition which affects the large intestine and is caused by a mutation in a gene. People with FAP develop many polyps (adenomas) which can in time turn cancerous.

Hereditary Non Polyposis Colon Cancer (HNPCC) is caused by a genetic mutation in the DNA. You may be at risk if you have family history of either FAP or HNPCC.


Colorectal cancer affects both men and women equally. It is mainly a disease of the over 50's but it can occur in younger people as well.

Previous Conditions

Patients who have had previous polyps removed or who have had cancer in the large intestine may be at an increased risk of colorectal cancer.

Inflammatory Intestinal Disease

People with a long history of Crohn's disease or Ulcerative Colitis may be at an increased risk of colorectal cancer.


Clinical evidence has proven that obesity is directly linked to colorectal cancer.

Diet and Lifestyle

A diet low in fibre and high in fat and a sedentary lifestyle can increase the risk of colorectal cancer.

It is important to remember that surgical and screening techniques are constantly improving as are drug therapies so there is a lot that can be done.