Bowel cancer

Find out more about bowel cancer

Bowel cancer is the second most fatal form of cancer after lung cancer, but the systematic policy of screening the over-50s is starting to bear fruit.
Bowel cancer is also known as colorectal cancer and is the most common cancer in men after prostate and lung cancer and the second most common in women after breast cancer. Bowel cancer is the generic term: in seven out of 10 cases it affects the colon (large bowel) and in three out of 10 it affects the rectum (back passage).

Bowel cancer prevention and screening

In nine out of 10 cases, bowel cancer can be successfully treated, provided that it is detected in time. As for many cancers, bowel cancer does not have specific symptoms. Indeed, outward signs of bowel cancer only occur when the cancer is at an advanced stage: abdominal pain and unusual and persistent digestive problems.

This is why people over the age of 50 need to be screened for bowel cancer every two years. It is wise to be screened at 40 as a preventive measure. A special test looks for tiny traces of blood in your stools that you will not be able to see with the naked eye. The French state health insurance scheme (Assurance Maladie) covers the cost of this diagnostic test. The attending physician gives the patient a kit. The patient takes a sample using a cotton bud and places it in a flask. The patient then posts the flask to a specialized laboratory. The attending physician receives the test results within two weeks. In 4% of cases, the test is positive, which leads to a care plan being put in place.

Colonoscopy – the test used to detect bowel cancer

If bleeding occurs, a gastroenterologist will conduct a colonoscopy to identify the origin of the bleeding. The test is performed under light general anesthetic. It can also be conducted in virtual 3D in specialized practices without the need for an anesthetic because the test is painless. The bowel will need to be completely empty for the gastroenterologist to examine its walls using a small camera. If the medical professional sees any benign growths (polyps), s/he will remove them before they develop into cancer. A biopsy is taken to detect early stage bowel cancer or a colon tumor in the event of there being any doubt.

If there is a family history of certain hereditary colorectal diseases, such as Familial adenomatous polyposis or Lynch syndrome, the doctor will prescribe an annual coloscopy. The doctor may also recommend a cancer genetics consultation in order to detect any genetic predispositions to cancer.


Before surgery, radiotherapy frequently combined with chemotherapy enables the tumor to be shrunk, making it easier to remove. The surgeon will remove the part of the colon or rectum affected by the tumor and lymph nodes, if possible preserving the anal sphincter. On average, people stay in hospital for seven to 10 days. Side effects (intestinal transit and sexual problems, pain, tiredness) may persist for several weeks. An anatomo-pathological examination of the tissue enables the extent of the disease to be detected and a decision to be taken as to whether radiotherapy will be needed to reduce the risk of local recurrence.


Institut National du Cancer, Le cancer du côlon : les points clés

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