Colorectal Cancer Screening in St. Louis
Colorectal cancer is the second leading cause of cancer death in the U.S. for men and women combined and is also one of the most preventable and detectable cancers when caught early. Screening changes everything.
Siteman Cancer Center leads the region in colorectal cancer screening, helping patients:
- Understand their personal risk and the right time to start screening
- Access the full range of screening options — from at-home stool tests to comprehensive colonoscopy, plus bringing screenings closer to home [LINK MOBILE UNIT PAGE]
- Receive results interpreted by expert WashU Medicine gastroenterologists and radiologists
- Connect directly with a WashU Medicine colorectal specialist at Siteman if screening reveals a concern
Why Is Colorectal Cancer Screening So Important?
Colorectal cancer almost always begins as a small, noncancerous growth called a polyp on the inner lining of the colon or rectum. Left undetected, some polyps can develop into cancer over years. Screening is the only way to find — and remove — polyps before that happens.
That makes colorectal cancer screening uniquely powerful: it doesn’t just detect cancer early. It can prevent cancer from developing in the first place.
When colorectal cancer is found at an early stage survivability is high at more than 90% at 5 years.
What If I Don’t Have Symptoms?
Colorectal cancer in its early stages often causes no symptoms at all. By the time symptoms like rectal bleeding, persistent bowel changes, or abdominal pain appear, the disease may be more advanced. That is precisely why screening matters — it finds cancer and pre-cancerous polyps before they make themselves known.
When colorectal cancer is caught early through screening:
- Treatment is significantly more effective
- Survival rates are substantially higher
- More treatment options are available, including minimally invasive surgery
- Treatment is often less intensive, with fewer side effects
When Should I Start Colorectal Cancer Screening?
The U.S. Preventive Services Task Force recommends that all adults at average risk begin colorectal cancer screening at age 45. If you have elevated risk factors, earlier and more frequent screening may be appropriate.
Average Risk: Start Screening at Age 45
You are considered average risk if you have no personal or family history of colorectal cancer or polyps, no inflammatory bowel disease, no known inherited genetic syndrome, and no symptoms. If this describes you, begin screening at age 45. How often you are screened after you begin depends on your test results.
Higher Risk: Start Screening before 45
Talk to your physician about starting screening before age 45 if you:
- Have a parent, sibling, or child who was diagnosed with colorectal cancer or advanced polyps. This is especially important if they had cancer before age 60.
- Have a personal history of colorectal cancer, colorectal polyps, or inflammatory bowel disease (Crohn’s disease or ulcerative colitis)
- Have been diagnosed with an inherited genetic syndrome such as Lynch syndrome (HNPCC) or familial adenomatous polyposis (FAP)
- Are African American
As a general guideline, higher-risk patients should begin screening 10 years before the earliest colorectal cancer diagnosis in their immediate family. For example, if a parent was diagnosed at age 45, you should start screening at age 35.
Your physician will recommend a specific screening schedule based on your individual risk profile. Ask about colorectal cancer screening at your next appointment.
Colorectal Cancer Screening Tests
Screening tests fall into two main categories: stool-based tests and visualization tests, like colonoscopy.
Colonoscopy — The Gold Standard
Colonoscopy is the most comprehensive and effective colorectal cancer screening test available. It is also the only test that can both find and remove polyps in the same procedure. It provides a complete view of the entire colon and rectum.
During a colonoscopy, your physician guides a thin, flexible tube with a small camera through the colon. If they find polyps or other abnormalities, they can be removed or biopsied immediately.
How often: Every 10 years for average-risk patients with no polyps found. These screenings are more frequent if polyps are detected or risk is elevated.
What to expect:
- You prepare the day before with a bowel preparation (“prep”) to clear the colon
- You will be sedated for the procedure for your comfort
- The procedure itself typically takes 30–60 minutes
- You will need someone to drive you home due to sedation
- Most patients return to normal activities the following day
At Siteman, WashU Medicine gastroenterologists and colorectal surgeons with extensive expertise perform colonoscopies.If your colonoscopy reveals a concern, you have immediate access to the region’s leading colorectal cancer specialists.
Stool-Based Tests — Convenient, At-Home Options
Stool-based tests are a practical alternative for patients who are unable or unwilling to undergo colonoscopy. They can be completed at home and do not require bowel preparation or sedation. If your stool-based test has a positive result, you will need a follow-up colonoscopy.
Fecal Immunochemical Test (FIT)
FIT uses antibodies to detect hidden blood in the stool. Blood is a potential indicator of polyps or colorectal cancer. It is simple, painless, and done entirely at home using a test kit from your physician. Siteman distributes FIT tests as part of our community commitment to screenings. Learn more here.
How often: Once a year.
Stool DNA Test (Cologuard®)
This test detects both hidden blood and abnormal DNA shed by cancer cells or advanced polyps into the stool. It combines the blood-detection capability of FIT with DNA biomarker analysis for higher sensitivity.
How often: Every 1–3 years.
High-Sensitivity Guaiac Fecal Occult Blood Test (gFOBT)
An older stool-based test that uses a chemical reaction to detect blood in the stool. Requires some dietary restrictions before the test and is collected at home.
How often: Once a year.
CT Colonography (Virtual Colonoscopy)
CT colonography uses a CT scanner and specialized software to produce detailed 3D images of the entire colon and rectum without inserting a scope. A small tube is placed in the rectum to gently inflate the colon with air, and the scan takes only a few minutes.
Unlike a traditional colonoscopy, CT colonography does not require sedation. However, bowel preparation is still required, and polyps cannot be removed during the procedure — a positive result will require a follow-up colonoscopy.
How often: Every 5 years.
Flexible Sigmoidoscopy
Flexible sigmoidoscopy uses a thin, lighted tube to examine the rectum and the lower portion of the colon (the sigmoid colon). It does not require sedation, but it cannot examine the upper portions of the colon, so it is a less comprehensive screening than a full colonoscopy.
If polyps or abnormalities are found, a follow-up colonoscopy is typically needed.
How often: Every 5 years, or every year when combined with an annual FIT test.
Colorectal Cancer Screening at Siteman
Siteman Cancer Center’s colorectal cancer screening program brings together the expertise of WashU Medicine gastroenterologists, radiologists, and colorectal surgeons to deliver the most accurate, comprehensive screening in the St. Louis region.
If a polyp is found and removed during your colonoscopy, our pathology team analyzes the tissue to determine if any further action is needed. You are never left to navigate next steps alone.
Contact information for Siteman Colorectal Cancer Screening Program: 314-747-3046