Risks, Causes & Symptons

Problems of the large bowel which is made up of the colon and rectum are very common although most symptoms do not turn out to be bowel cancer. However, if you have any of the following symptoms that persist for more than a few weeks, talk to your doctor:

  • bleeding from your bottom and/or blood in your poo
  • a change in bowel habit lasting three weeks or more
  • unexplained weight loss
  • extreme tiredness for no obvious reason
  • a pain or lump in your tummy

Why do you need to know the symptoms? Bowel cancer is very treatable, but like most cancers, the earlier it is diagnosed the more effective treatment is likely to be. People whose cancer has not spread beyond the inner lining of the bowel have a much higher chance of successful treatment compared to those whose cancer has become more widespread. So if you have any of the symptoms listed above don’t be embarrassed and don’t ignore them. Go and see your doctor. What are the risk factors? Doctors and researchers don’t yet know the exact cause of bowel cancer. But we do know that certain factors contribute to a higher risk.

Bowel cancer can develop in men and women of any age but it tends to be a disease of middle and old age. In New Zealand the majority of cases occur in people over the age of 45. Diet and lifestyle are increasingly seen as important. Increasing evidence shows that a diet high in red meat and/or processed meat and low in fibre (lacking in vegetables, fruit and whole grains) increases the risk of developing bowel cancer. Other risk factors related to lifestyle are obesity, lack of exercise, high alcohol consumption and smoking. Research shows that overweight or obese people have an increased risk of bowel cancer. People who have inflammatory bowel diseases such as ulcerative colitis or Crohn’s disease or those with a tendency to develop polyps (overgrowths of cells in the lining of the bowel) may be more susceptible to developing bowel cancer.

People who have a family history of cancer may have an increased risk of bowel cancer, athough only a small number of cases are related to family history.

Some risk factors such as age or family history are out of your control.