What is a colonoscopy?
Colonoscopy is the most accurate test to detect abnormal growths (colon polyps) in the large intestine as well as colon cancer. It is the only test where polyps can be removed.
During colonoscopy, a slender flexible tube, called a colonoscope, is inserted into the anus and then slowly advanced through the colon. Carbon dioxide is used to inflate the large intestine, and a video image is transmitted from the scope to a video monitor. This procedure allows the physician to examine the inside of the large intestine for disease.
Small pieces of any abnormal tissue can be removed through the colonoscope, and precancerous growths, called polyps, can be excised. This is important, as the vast majority of colon cancer cases arise from benign colon polyps.
Colon cancer is the second-most common cancer in the United States. More than 55,000 people die annually from colon cancer. There is a 5 percent lifetime risk of developing colon cancer, though the disease can largely be prevented by the removal of polyps at the time of a colonoscopy screening.
During the colonoscopy, patients lie on their left side on an examination table. In most cases, a nurse anesthesiologist administers a sedative to reduce pain and to keep patients relaxed. Vital signs are monitored throughout the procedure. Colonoscopy usually takes between 30 and 60 minutes to complete. Following the procedure, patients generally spend an additional 30 to 60 minutes at the endoscopy center to allow the sedative to wear off. Normal activities can resume the following day. Driving is not allowed for 24 hours following a colonoscopy.
Who should get a colonoscopy and when?
Most patients will undergo their first colonoscopy between the ages of 40 and 50, depending on symptoms, family history and race. Colon cancer can be prevented more than 90 percent of the time if precancerous polyps are removed when they are still small.
Healthy white patients are advised to undergo colonoscopy at age 50, while healthy African-Americans are encouraged to undergo screening beginning at age 45. Patients with symptoms such as rectal bleeding, anemia or other symptoms like weight loss or a change in bowel habits should receive a colonoscopy at an earlier age, as should patients who have a family history of colon cancer.
Is the preparation for a colonoscopy procedure really difficult?
Many patients are reluctant to undergo colonoscopy due to misconceptions regarding the prep that is required. The large intestine needs to be thoroughly cleansed prior to the procedure. Modern preps are much more palatable and of lower volume than in the past. While not enjoyable, most patients have no problem tolerating the new preps.
Another concern of patients is the cost. Medicare and most private insurance companies now offer preventive screening colonoscopy benefits, meaning screening colonoscopies are often available at little or no cost to the patient.
What does a colonoscopy screen for? Is it painful?
A colonoscopy is generally very safe. As with any medical procedure, there are some risks. Major complications can occur in about one out of every thousand colonoscopies and include perforation, pneumonia and bleeding.
Colonoscopy is one the few procedures that have been shown to be cost-effective and lifesaving. Even in the absence of any symptoms, a colonoscopy should be performed at either age 45 in African-Americans or age 50 in Caucasians. Speak to your family physician regarding screening colonoscopy at the time of your next visit.