Screening also enables your healthcare provider to find and remove any growths before they become cancerous.
A colonoscopy is a standard screening tool for colon cancer, but there are other screening methods too.
What Happens During a Colonoscopy?
Photo Illustration by Michela Buttignol for Verywell Health; Getty Images
It is used to screen for colon cancer and other colon problems.
A clean colon is necessary for a successful colonoscopy.
You will need to restrict your diet for at least 24 hours before your appointment.
You will also need toempty your bowel.
Your doctor might suggest a laxative or enemas.
You will need to do this the night before the colonoscopy.
Be sure to follow all your doctors directions closely.
Make arrangements for someone to take you home after the colonoscopy.
The colonoscopy is performed by agastroenterologist, a doctor specializing in disorders of the digestive tract.
The procedure lasts about 30 to 60 minutes.You will be given sedation medication through a vein in your arm.
The colonoscope is inserted through the rectum and advanced to the colon.
It bends so it can be moved around to examine the colon.
It also blows air into the colon to help the colon expand so it can be viewed more clearly.
If any polyps are discovered, they are removed during the procedure.
Colon Cancer Screening Methods
A colonoscopy is not your only option for screening for colon cancer.
It can also screen for colon and rectal cancers.
The sigmoidoscopy uses a thin, flexible tube called a sigmoidoscope that has a tiny light and camera.
The tube is also used to blow air into the colon to make it swell up and improve visibility.
Much like a colonoscopy, you will need to prepare in advance of the procedure.
You should stop eating solid foods for at least eight hours before.
You will also need to clear out your colon using the enema before the procedure.
You will need someone to drive you home because you will be sedated for the procedure.
Virtual Colonoscopy
A virtual colonoscopy helps your doctor see the inside of the colon and rectum.
It is used to look for polyps and check for colon and rectal cancers.
This test doesnt involve sedation, but some preparation is necessary.
To prepare, your doctor may recommend some diet changes.
Unfortunately, the test is not always accurate, and a positive test might require a follow-up colonoscopy.
The stool DNA analysis will look for multiple DNA markers and mutations using sensitive methods for detection.
Stool DNA testing has high detection rates for colon cancer in its earliest stages.
Blood DNA Tests
People at average risk for colorectal cancer can be screened with a blood test.
These tests look for cell-free DNA that indicates possible colorectal cancer or pre-cancerous polyps.
The two FDA-approved tests are Shield and Epi proColon.
They know your personal and family history with cancer and any additional risk factors.
They will recommend you start getting screened at age 45.
If you have an average risk for colon cancer, your healthcare provider might recommend an at-home screening method.
These home-collected tests are convenient, easily accessible, and effective.
But if these tests detect anything, you will need a follow-up colonoscopy.
A full colonoscopy is the most accurate screening method.
But it requires preparation, sedation, and one or two days away from work.
Depending on what part of the colon your doctor wants to see, a sigmoidoscopy might be considered.
If time is a problem for you, a virtual colonoscopy might be an alternative to a full colonoscopy.
This procedure images the rectum and colon and can be as accurate as a colonoscopy.
But if this test reveals polyps or other abnormal growths, you will need a colonoscopy to remove them.
Considering the Pros and Cons
There is no best screening method for colon cancer.
Each test has benefits and drawbacks.
Colon cancer screening is not recommended after age 85.
Screening frequency depends on the testing method or combination of tests.
Summary
Screenings are your best preventive method for colon cancer.
Testing can detect polyps and abnormal tissue early and long before you develop symptoms.
Your doctor can recommend a screening method based on your risk factors and preferences.
A Word From Verywell
It can be stressful and scary if you are diagnosed with colon cancer.
Your treating doctor can discuss typical outcomes for your cancer.
It cannot predict your specific prognosis or outlook.
Additionally, because of advanced and improved treatment methods, the outlook for colon cancer is improving every day.
Frequently Asked Questions
Studies have found at-home stool tests for colon cancer to be reliable.
You have different options for at-home testing and each of these has its unique level of accuracy.
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National Institute of Diabetes and Digestive and Kidney Diseases.Virtual colonoscopy.
MedlinePlus.Fecal immunochemical test(FIT).
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doi:10.1016/j.cgh.2017.01.025
Colorectal Cancer Alliance.Stool DNA.
Exact Sciences.ExactSciences applauds final task force recommendation that lowers starting age for colorectal cancer screening to 45.
American Cancer Society.Colorectal cancer screening tests.
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