Bowel cancer screening

Bowel cancer often starts out with small, noncancerous polyps in the large intestine (bowel) that don’t produce symptoms. Therefore, it’s recommended you receive screenings to identify and remove polyps before they become cancerous.

Bowel cancer can occur at any age, however, it’s most common in older adults. If you do develop bowel cancer, your doctor will work with you to tailor a treatment plan to your specific cancer and needs. The plan may include a combination of radiation, surgery and drug treatments, such as chemotherapy, targeted therapy and immunotherapy.

See your doctor if you have any typical signs and symptoms of bowel cancer, such as:

  • A persistent change in your bowel habits, such as constipation or diarrhea or a change in stool consistency
  • Blood in your stool
  • Rectal bleeding
  • Ongoing abdominal discomfort, such as gas, pain or cramps
  • A feeling that your bowel doesn't empty completely
  • Weakness or fatigue
  • Unexplained weight loss

When should you be screened for bowel cancer?

Talk to your doctor about screening options to catch bowel cancer before it starts. In general, people should start regular screenings around 50. However, your doctor may recommend you start screenings at an earlier age or have them more frequently if you are in a high-risk group, such as having a family history of bowel cancer.

Risk factors include:

  • Older age
  • History of bowel cancer or polyps
  • History of inflammatory intestinal conditions
  • Inherited syndromes that increase bowel cancer risk, such as familial adenomatous polyposis (FAP) and Lynch syndrome, which is also known as hereditary nonpolyposis colorectal cancer (HNPCC)
  • Family history of bowel cancer
  • Low-fibre, high-fat diet
  • A sedentary lifestyle
  • Diabetes
  • Obesity
  • Smoking
  • Alcohol

How do you test for bowel cancer?

Your doctor will discuss with you screening options that best fit your needs. Options at Mayo Clinic Healthcare include:

  • Colonoscopy, which uses a camera on a long flexible tube inserted into the rectum. (Read more about colonoscopy at Mayo Clinic Healthcare.)
  • Faecal occult blood test (FOBT) and faecal immunochemical test (FIT), which use stool samples to find hidden (occult) blood.
  • Virtual colonoscopy, which uses a CT scan to produce cross-sectional images of the abdominal organs, allowing the doctor to detect changes or abnormalities in the colon and rectum. To help create clear images, a small tube (catheter) is placed inside your rectum to fill your colon with air or carbon dioxide.

Mayo Clinic Healthcare will work with you to determine if bowel cancer screening is right for you and, if so, which options best suit your needs and preferences.