Colorectal cancer is the third most common cancer in both men and women in the United States. The gold standard screening procedure for colon cancer is a colonoscopy, a test that allows your doctor to examine the inner lining of the large intestine (rectum and colon) for polyps, ulcerations, diverticulosis and early signs of cancer.
“Unlike other screening tests, a colonoscopy actually prevents cancer by allowing us to find and remove lesions before they become problematic,” said Dr. Jessica R. Allegretti, a gastroenterologist in the Division of Gastroenterology, Hepatology and Endoscopy at Brigham and Women’s Hospital.
In fact, due to increased awareness about screenings, the death rate from colorectal cancer has been dropping for more than 20 years.
Why do I need a colonoscopy?
During a colonoscopy, the doctor examines the lining of the colon, looking for polyps that appear abnormal. The screen will detect polyps in on average 30 to 40 percent of men, and 20 to 30 percent of women.
“Not all of these polyps will become cancerous, but a vast majority of them have the ability to. Regardless, it’s important to get them out before they become an issue,” said Dr. Allegretti.
When should I get a colonoscopy?
The American Cancer Society recommends that both men and women undergo a colonoscopy every 10 years, beginning at age 50. If you have a family history of colon cancer or other genetic risk factors, screening may start earlier.
According to the Centers for Disease Control and Prevention (CDC), as many as 60 percent of colon cancer deaths could be prevented if everyone 50 years old or above underwent colonoscopies.
The findings of a colonoscopy will determine when the next colonoscopy should be scheduled. If polyps are not found, another colonoscopy isn’t necessary for 10 years. If polyps are found, the follow-up should happen sooner (anywhere from one to five years depending on the number of polyps removed). Most guidelines recommend screening stop between ages 75 and 85.
How should I prepare for a colonoscopy?
“Bowel preparation is the most important part of the exam, because a clean colon allows us to see and remove polyps,” said Dr. Allegretti.
To ensure that the inside of the colon is clean, a patient must take a laxative the day before the procedure. The standard bowel prep at the Brigham consists of mixing Miralax, an over-the-counter laxative, with two 32-ounce sports drinks and two Ducolax tablets.
“We also recommend going on a low fiber diet the week before the test, meaning avoiding raw vegetables or high fiber foods because those can hang around the colon for quite awhile and make the cleaning of your colon more difficult,” said Dr. Allegretti.
How does the exam feel?
Many people fear colonoscopies, but the procedure is brief and relatively painless.
“You will have an IV placed in your arm and be given sedation that makes you sleepy and comfortable. We generally use something called IV conscious sedation, so you’re not completely asleep like you might be for a surgery, but you’re very comfortable and almost in a twilight state,” said Dr. Allegretti.
During the procedure, an endoscope — a long, flexible, lighted tube — is inserted into the rectum and gently advanced through the intestine. Your doctor may remove tissue or polyps for further examination. He or she may also be able to treat problems that are found such as bleeding. The procedure generally lasts about 30 to 40 minutes.
Brigham and Women’s Hospital: A leader in colonoscopy and colorectal disease treatment
For patients in the greater Boston area and the New England region, the Endoscopy Center at the Brigham offers the colonoscopy exam in a state-of-the-art medical facility that is recognized as one of the leading endoscopic centers in the country.