Timely, regular screening can prevent colorectal cancer

Colorectal cancer is the fourth-most common cause of cancer in the United States. It is a preventable disease that is reduced with the use of timely, regular screening.

In general, colorectal cancer arises from precancerous colon polyps. The role of colonoscopy is to identify and remove colon polyps, thereby removing potential cancers before they ever start.

Timely colonoscopy also helps to identify cancers in early stages. When identified and treated early, up to 90% of patients can be cured of cancer.

However, when cancer has progressed enough to cause symptoms like GI bleeding, pain, or a change in bowel habits it is usually advanced with a lower chance of cure.

Who is at risk for developing colorectal cancer?

The lifetime risk of developing colorectal cancer in the general population is approximately 5%; however, people with a personal or family history of colorectal cancer or a personal history of colon polyps are at increased risk of developing colon cancer.

People with a personal history of having other cancers or who have chronic medical conditions including ulcerative colitis or Crohn's disease are at increased risk compared to the general population.

Smoking also increases your risk of developing colorectal cancer.

When to start getting screened for colorectal cancer?

Everyone needs to undergo screening for colorectal cancer and the timing and frequency of screening is determined by the level of individual risk.

For people without risk factors, the "gold standard" for screening is colonoscopy beginning at age 50 years. In general, colonoscopy is repeated every 10 years or less depending on findings. Alternatively, a flexible sigmoidoscopy can be performed every five years with yearly stool occult blood testing beginning at age 50 years.

For people with a family history of colorectal cancer or polyps, colonoscopy should be performed at age 40 or 10 years earlier than the age of the youngest diagnosed relative. Colonoscopy is generally repeated every five years or less depending on findings.

In people with a rare inherited colorectal cancer syndrome, screening begins much earlier in life and is performed more frequently due to a substantially increased risk.

Colorectal cancer screening options

Colonoscopy is the "gold standard" method for colon cancer screening. This is because colonoscopy allows your surgeon to see the entire length of the colon and remove precancerous polyps and sample any suspicious findings for further examination.

Colonoscopy is a safe and effective and is typically performed under sedation for your comfort.

When colonoscopy cannot be performed for various reasons, flexible sigmoidoscopy can be offered in combination with yearly stool occult blood testing.

Flexible sigmoidoscopy uses a shorter scope and only looks at the lower third of the colon. If any findings are seen on flexible sigmoidoscopy, a colonoscopy must be performed to look at the entire colon.

Virtual colonoscopy is a CT scan that generates an outline of the colon and identifies possible polyps. This is a non-invasive test that can be used as an initial test; however, a colonoscopy is needed if any findings are seen on virtual colonoscopy. This test may not be available at your institution and may not be covered by insurance.

Preparing for your colonoscopy

When you call the office to schedule a colonoscopy, your scheduler will review a preliminary medical checklist with you.

In some cases, it will be necessary to schedule a clinic visit with a colorectal surgeon before getting scheduled for a colonoscopy.

In general, a bowel preparation is needed to cleanse the colon and remove all debris that makes it hard to see the lining of the colon. The bowel preparation is usually started one or two days before your procedure. A diet of clear liquids is recommended while you are completing your preparation.

It is important to complete the preparation as instructed and to call your surgeon's office before the day of the procedure if you are having any issues.

What to expect during your colonoscopy

Most people receive sedation for comfort during the procedure. Sometimes this medication can cause you to fall asleep or forget the details of the procedure.

The colonoscope is a long flexible tube with a light and camera at the end. This end is inserted into the rectum and advanced carefully to the start of the colon. The scope is then withdrawn and the lining of the colon is carefully inspected.

In general, this procedure takes less than an hour and a short period of time is needed after the procedure for monitoring.

You will need a friend or family member to drive you home as you may be tired or have impaired judgment as a result of the sedation.

Most people are able to resume normal activity the following day.