Colorectal cancer screening saves lives
3/17/2025 by Sara Shu, D.O.
Colorectal cancer is the third most common cause of cancer, and it's preventable. Screening can detect pre-cancerous colon polyps (abnormal tissue growth) and safely remove them before they develop into cancer.
Who should be screened for colorectal cancer?
- Adults ages 45-75 years with an average risk of colorectal cancer. Previously, screening started at 50. This recommendation was adjusted because the incidence of colorectal cancer at a younger age has increased.
- After 75 years, the decision to continue screening should be personalized.
If you have any of the following, you would not be considered average risk:
- Personal or family history of colorectal cancer or high risk for polyps.
- A genetic disorder causing a high risk of colorectal cancer or inflammatory bowel disease.
What are the options for colorectal cancer screening?
- Colonoscopy: Considered the gold standard. This test requires prior use of bowel cleansing preparation and a scope to look for and remove polyps in your entire colon and rectum. Colonoscopies should be repeated every 10 years or more frequently, depending on the type and number of polyps found.
- 2-step screening tests: Any positive test requires a follow-up colonoscopy.
- FIT (Fecal Immunochemical Test): This stool-based test detects hidden blood in the stool. Completed annually.
- Multitarget stool DNA test (Cologuard): A non-invasive stool-based DNA test looking for abnormal DNA associated with colon cancer or precancerous polyps. Completed every three years if normal.
- Computed tomography (CT) colonography: An imaging modality that requires colon cleansing preparation and oral contrast agents. It may be reasonable in select circumstances.
What are the symptoms of colorectal cancer?
- Most commonly, early cancers do not cause symptoms, which is why it is important that you get screened.
- Symptoms include bright red or black blood in the stool, change in bowel habits (constipation), change in stool shape and size, abdominal or rectal pain, fatigue from low blood counts (anemia) and unexplained weight loss.
March is Colorectal Cancer Awareness Month. Speak with your healthcare clinician about getting colorectal cancer screening today.
Sara Shu, D.O., is a board-certified family medicine physician and geriatrician-in-training in Community Internal Medicine, Geriatrics and Palliative Care at Mayo Clinic in Rochester.