About 6 per cent of the population in Western countries develop bowel cancer at some time during their lives, making this the second commonest cause of cancer-related death. However, it is curable in 40-50 per cent of cases, usually by surgery.
The average age when bowel cancer is first discovered is 65, and it becomes increasingly common with advancing age. Very occasionally, it may affect much younger adults from the age of 20.
About 90 per cent of the risk for bowel cancer is thought to be due to dietary factors, with the other 10 per cent due to genetic (inherited) factors.
Bowel is the general term for the long muscular tube that starts at the bottom of the stomach and ends at the anus. The first part of the bowel is involved with the digestion of food and is known as the 'small bowel' because the tube is narrower here. The 'large bowel' follows the small bowel and in a healthy person, the main part of the large bowel (colon) is responsible mostly for absorbing water from the faeces. The last part of the large bowel is known as the rectum, which leads to the anus.
About 85 per cent of people with bowel cancer are currently not diagnosed until the cancer has penetrated through the bowel wall or spread to lymph nodes or elsewhere. Cure is nevertheless still possible. The earliest symptom is often bleeding from the back passage. Later changes include loss of the normal form of bowel motions sometimes followed by diarrhoea
The best available approaches for a low risk of developing bowel cancer are:
• a diet high in green vegetables, particularly cabbage, broccoli, brussel sprouts or cauliflower.
• a diet low in red meat. In particular, avoid burnt meat, which contains cancer-promoting chemicals called cyclic amines