Search the Health Library
Get the facts on diseases, conditions, tests and procedures.
I Want To...
I Want To...
Find Research Faculty
Enter the last name, specialty or keyword for your search below.
School of Medicine
I Want to...
Colon Cancer: Q&A with a Gastroenterologist
When’s the best time to get a colon cancer screening? And is it really necessary? (Spoiler alert: Yes!)
Johns Hopkins gastroenterologist Francis Giardiello, M.D., answers patients’ most common questions about colon cancer screening.
Q. How do I know which colon cancer screening is right for me?
A: There’s an array of screening options available. These include:
- Colonoscopy: In this procedure, a doctor uses a long scope with a camera to check your colon for polyps.
- Various stool sample tests: Most of these test your stool for blood.
- Virtual colonoscopy: This is a CT scan of your colon that checks for polyps.
Each screening has risks and benefits. Doctors today recommend most healthy people get a colonoscopy starting at age 50. If nothing abnormal is found, you probably won’t need another screening for 10 years.
One big benefit to a colonoscopy is that if any polyps are found, they can be removed at the same time. No additional procedure is necessary. Your primary care doctor can discuss with you the colon cancer screening options available today.
Q. What is the prep for a colonoscopy?
A: The day before your colonoscopy, you’ll need to restrict your diet. You’ll drink a liquid that will help clear your bowels. This may mean multiple bathroom trips as your colon clears.
This prep process before your colonoscopy can be unpleasant. It may even last longer than the colonoscopy itself.
But it’s important. Following all prep instructions by your doctor will help ensure he or she can see your colon clearly, which then helps to spot anything abnormal.
Q. Will a colonoscopy be covered by my insurance?
A: In general, yes. You should check with your insurance provider for specifics on which types of colon cancer screenings it covers and at what ages.
Q. Are there any other ways I can prevent colon cancer?
A: Getting a colon cancer screening is the single most effective way to prevent colon cancer. In addition, studies have shown your diet and lifestyle can also lower your colon cancer risk:
- Eat lots of fruits and vegetables.
- Eat yogurt regularly.
- Avoid or limit red meat.
- Exercise regularly.
Q. My recent colonoscopy showed a few nodules that my doctor is testing. Should I be worried?
A: Not necessarily. Usually when colon cancer is present, there is a large lesion or a large mass in a lesion. If your colonoscopy shows a few nodules, the risk of the nodules being cancerous is very small.
Q. Is colon cancer genetic?
A: In 20 percent of colon cancers, there is some hereditary link. If anyone in your family has been diagnosed with colon cancer (especially at a young age), you should tell your doctor.
He or she may want to monitor you more closely because of your family history. That could mean more regular colon cancer screenings to catch any disease early.
Patient Perspectives | Gary Waymire – Colorectal Cancer
After a large polyp was discovered in Gary Waymire's rectum following a routine colonoscopy, he sought a second opinion at The Johns Hopkins Hospital. Jonathan Efron, M.D., director of colorectal surgery, and his multidisciplinary team used a series of aggressive and innovative surgical procedures as part of Gary’s treatment. Now cancer-free, Gary makes the most out of life’s simple pleasures, including walking 8 to 9 miles each day and spending precious moments with his wife at home in Virginia.