Bowel cancer is a general term for cancer that begins in the large bowel. Depending on where in the bowel the cancer starts, bowel cancer is sometimes called colon cancer or rectal cancer.
Symptoms of bowel cancer include blood in your stools (faeces), an unexplained change in your bowel habits, such as prolonged diarrhoea or constipation, and unexplained weight loss.
Cancer can sometimes start in the small bowel (small intestine), but small bowel cancer is much rarer than large bowel cancer.
The large bowel
The bowel is part of the digestive system. It has two main purposes:
- to absorb energy, water and nutrients from the food you eat
- to pass out the remaining waste products from your body in the form of stools
The large bowel is made up of five sections:
- The ascending colon runs from the end of the small intestine and up the right-hand side of the abdomen.
- The transverse colon runs under the stomach and across the body from right to left.
- The descending colon runs down the left-hand side of the abdomen.
- The sigmoid colon is an S-shaped bend that connects the descending colon to the rectum.
- The rectum is the final section of the bowel. It is a small pouch that is connected to the outside opening of the bowel (the anus), through which stools are passed.
How common is bowel cancer?
In England, bowel cancer is the third most common type of cancer. In 2008, there were 39,991 new cases of bowel cancer registered in the UK:
- 17,894 cases were diagnosed in women, making it the second most common cancer in women after breast cancer
- 22,097 cases were diagnosed in men, making it the third most common cancer after prostate and lung cancer
Approximately 80% of bowel cancer cases develop in people who are 60 or over. Two-thirds of bowel cancers develop in the colon, with the remaining third developing in the rectum.
In England, an estimated 16,000 people die from bowel cancer each year.
Factors that increase your risk of getting bowel cancer include:
- Age: around 80% of people diagnosed with bowel cancer are over 60.
- Diet: a diet high in fibre and low in saturated fat could reduce your bowel cancer risk. A diet high in red or processed meats can increase your risk.
- Healthy weight: leaner people are less likely to develop bowel cancer than obese people.
- Exercise: being inactive increases the risk of getting bowel cancer.
- Alcohol and smoking: high alcohol intake and smoking may increase your chances of getting bowel cancer.
- Family history and inherited conditions: having a close relative with bowel cancer puts you at much greater risk of developing the disease.
- Related conditions: having certain bowel conditions can put you more at risk of getting bowel cancer.
Bowel cancer screening
In 2006, the NHS launched a screening programme for bowel cancer. It is recommended that everyone between the ages of 60 and 69 is screened every two years.
Screening is carried out by taking a small stool sample and testing it for the presence of blood.
Screening plays an important part in the fight against bowel cancer because the earlier the cancer is diagnosed, the greater the chance that it can be cured completely.
For more information, see Bowel cancer - screening.
Outlook
Bowel cancer can be treated using a combination of surgery, chemotherapy, radiotherapy and, in some cases, biological therapy. As with most types of cancer, the outlook for an individual depends largely on how far the cancer has advanced by the time it is diagnosed.
If bowel cancer is diagnosed in its earliest stages, the chances of surviving for a further five years is 90%, and a complete cure is usually possible. However, bowel cancer that is diagnosed in its most advanced stage only has a five-year survival rate of 6% and a complete cure is unlikely.
Screening can diagnose cancer at its earliest stage and can increase the chance of successful treatment.
Want to know more?
