What are the risk factors for bowel cancer?

A risk factor is any factor that is associated with increasing someone’s chances of developing a certain condition, such as cancer. Some risk factors are modifiable, such as lifestyle or environmental risk factors. Others cannot be modified, such as inherited factors or whether someone in the family has had cancer. 

Having one or more risk factors does not mean you will develop cancer. Many people have at least one risk factor but will never develop cancer, while others with cancer may have had no known risk factors. Even if a person with cancer has a risk factor, it is usually hard to know how much that risk factor contributed to the development of their disease. 

Bowel cancer risk factors 

Both men and women are at risk of developing bowel cancer. The risk is greater if you: ^[3][4][5]

• are aged 50 years or over – your risk increases with age 
• have had an inflammatory bowel disease, such as Crohn’s disease or ulcerative colitis 
• have previously had special types of polyps, called adenomas, in the bowel 
• have previously had any type of bowel cancer 
• have a significant family history of bowel cancer or adenomatous polyps. 

Other risk factors include: ^[6][7][8]

• excess body fat and physical inactivity 
• high intake of particular foods (such as red and processed meats) 
• a low blood level of vitamin D 
• high alcohol consumption; even low alcohol consumption may be associated with some risk of developing bowel cancer 
• smoking 
• some gene mutations 
• type 2 diabetes. 

Anyone, including younger people, with concerns about their risk of developing bowel cancer should talk to their doctor. ^[9][10][11]

Find out more 

• Lifestyle and risk reduction 
• Check Your Cancer Risk – online tool 
• Cancer Australia position statement: Lifestyle risk factors and the primary prevention of cancer