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Your Questions — 7 minutes

Fecal blood testing and colorectal cancer

September 16, 2024

Does a positive fecal blood test result necessarily mean that a person has colorectal cancer?

No. Several other conditions can cause blood in the stool: hemorrhoids, anal fissures, constipation or inflammatory bowel disease can also yield positive results.

Does a negative fecal blood test result rule out the possibility of colorectal cancer?

No. Polyps and tumours do not continuously discharge blood. It is possible that a lesion did not bleed on the day a sample was taken. For this reason, Quebec’s colorectal cancer screening program recommends testing at least every two years.

Is fecal blood testing used for diagnosis?

No. Fecal blood testing is used for screening purposes. Only an optical or virtual colonoscopy can diagnose the presence of a polyp, adenoma or cancerous lesion.

Taking the FIT test every 2 years is the best way to prevent colorectal cancer. Validate your eligibility for the screening program now.

Are optical colonoscopy (insertion of a tube into the rectum) and virtual colonoscopy (radiological exam) equally valid for diagnosing the presence of colorectal cancer?

Yes. The performance of both approaches is similar. However, with optical colonoscopy, if polyps are present, they can be removed during the procedure, which is not the case with virtual colonoscopy. On the other hand, virtual colonoscopy can be used to diagnose other abdominal lesions not visible with optical colonoscopy (ovarian cysts, etc.).

Isn’t colorectal cancer essentially a disease that affects the elderly?

No. Although colorectal cancer is most often diagnosed in people over the age of 60, the incidence of colorectal cancer in people under age 50 appears to be rising steadily in North America.

If you are younger than 50 and would like to take the FIT screening test, you must have a family history or specific risk factors to be eligible for the screening program. You can confirm your eligibility by completing this short questionnaire.

Is red meat responsible for colorectal cancer?

Yes. An American study of 500,000 retirees showed that those who consumed the most red meat were 30% more likely to develop colorectal cancer. Among heavy consumers of processed meats (e.g., bacon, sausage, deli meats), the risk was up to 20 times higher.

Isn’t colorectal cancer a disease that only affects men?

No. Cancer rates in men and women are very similar: one in sixteen men and one in eighteen women are likely to develop this cancer in their lifetime.

Does eating fish protect you against developing colorectal cancer?

Several studies suggest that the omega-3s present in fish have a protective effect against colorectal cancer. In any case, adding fish to the diet helps reduce the consumption of red or processed meat.

Is even reasonable alcohol consumption (no more than three glasses a day for men) associated with the development of colorectal cancer?

Alcohol consumption is definitely a risk factor for colorectal cancer. There is no defined minimum quantity below which the risk disappears completely.

Isn’t colorectal cancer an unpreventable hereditary disease?

Approximately 5% of colorectal cancers are believed to be genetic in origin. The vast majority of cases are due to poor lifestyle habits. Many studies indicate that simple measures can greatly reduce the risk of developing colorectal cancer:

  • Be physically active.
  • Maintain a healthy weight.
  • Limit the consumption of red and processed meats.
  • Limit alcohol consumption.
  • Choose high-fibre foods (fruits, vegetables, whole-grain cereals).
  • Get screened regularly for blood in the stool.
  • Don’t smoke.

Please feel free to complete the questionnaire to confirm your eligibility for the fecal immunochemical test (FIT) without a medical prescription.

For professional support, we’re here for you.

We provide services that can help your doctor diagnose irritable bowel disorders and related health problems and determine the appropriate treatment.

Do you have a medical prescription for any of these tests? Book an appointment online or contact Biron Health Group’s customer service at 1 833 590-2712.

This revised edition reflects an updated version from the original version published on our website. We have incorporated recent facts to offer you current and pertinent information.