COLONOSCOPY - SHOULD YOU HAVE ONE?

When her doctor suggested that she have a colonoscopy to screen for colorectal cancer, Pam said she wanted time to think about it. A year later, as she makes an appointment for her yearly checkup, she’s uneasy about having to come up with a new excuse.

Pam has heard all the anecdotes; she’s uncomfortable even at the thought of having a camera exploring the inside of her bowels. On the other hand, she has a cousin who was treated successfully for colon cancer and credits colonoscopy as saving his life.
Colonoscopy uses a thin, flexible tube with a light and camera attached to examine the lining of the large intestine (rectum and colon). The procedure can be used to help diagnose abnormalities such as ulcers, polyps, tumors and areas of inflammation or bleeding.

Not all abnormalities in the colon are cancerous, but all cancers start as adenomatous polyps. If detected early enough, these polyps can be removed before they become malignant.

Generally recognized as the best way of detecting polyps, colonoscopy is one of three widely used and recommended screening tests for colon and rectal cancer.
As opposed to fecal occult blood testing (FOBT)–a simple take-home test that requires collecting stool samples and sending them in for laboratory testing–colonoscopy is more invasive but capable of detecting actual polyps as opposed to hidden bleeding in the bowels that might or might not be caused by a polyp. Because it’s non-invasive and inexpensive, FOBT is sometimes used a preliminary test, to be followed by colonoscopy if occult or hidden bleeding is discovered.

Compared to sigmoidoscopy, which examines just the rectum and the lower third of the colon, colonoscopy gives a doctor a chance to observe the lining of the entire large intestine. Polyps can exist anywhere in the colon.

For persons over age 50, the American Cancer Society recommends either:

• A yearly FOBT plus sigmoidoscopy once every five years,

• colonoscopy once every 10 years

• or a barium enema once every five years. In most areas, the barium enema is no longer widely used.

Persons with a moderate to high risk of colon or rectal cancer are advised to have more frequent screening. Most at risk are persons who have already had a precancerous polyp removed or who have a close relative diagnosed with colorectal cancer.

Don’t Die of Embarrassment
Pam knows her decision should be an easy one. But even though a colonoscopy is not painful, it does involve significant discomfort lasting several days.

To prepare, it’s necessary to clear the bowels, and many consider this the most difficult part. Pam’s friends told her about not being able to eat solid foods for a day or two followed by use of laxatives and enemas–“not a very pleasant experience,” they said. In most cases, the preparation has been considerably simplified since that time.

One method involves drinking a gallon of very salty solution within one or two hours.
This does a good job of flushing the colon without adding or subtracting any fluids from the body. Some individuals find it difficult to drink that much fluid, however. Alternatives include:

• taking four prescription laxative tablets every 15 minutes–for a total of 20–the night before the colonoscopy plus additional tablets the next morning about three hours before the procedure,

• four laxative tablets followed by half a gallon of the salty solution, or

• sodium phosphate in half a gallon of water.

In most cases, the enemas are no longer necessary, although the patient requires time off from work for the frequent trips to the bathroom.

The colonoscopy itself takes about half an hour and is performed under sedation, usually given intravenously. Even though you’re conscious, you’re likely to be groggy and not remember much of the procedure.

As with bowel preparation, Pam could expect significantly less discomfort than her friends remembered. The trend is toward deeper sedation and, with improving technology, the test can be performed more efficiently with fewer complications.
Although sigmoidoscopy is a less invasive procedure, it usually does not require sedation and, as a result, may be more uncomfortable–though it is certainly not painful. And it also requires clearing the bowels so the lining can be clearly visualized on the monitor.

Becoming available only recently is an alternative known as virtual colonoscopy. Rather than using the scope to explore the bowel, this method uses x-ray, CT and MRI technology to construct two- and three-dimensional images.

Virtual colonoscopy is not widely available, however, and results have not been found as consistently reliable. In addition, this procedure requires the same bowel cleaning preparation plus insertion of air into the colon–which can cause discomfort.

In the future, there will undoubtedly be ways of screening that eliminate both the probing and the preparation...but none of these are approved and available today.
One major advantage of colonoscopy is that when a cancerous or precancerous polyp is detected, it can be removed or biopsied on the spot. Larger cancers may require surgery to remove a section of the colon, and this would be performed at a later time. Follow-up colonoscopies are then required to check for recurrence.

Colonoscopy carries a slight risk of puncturing or damaging the wall of the colon, and it’s more expensive than sigmoidoscopy or barium enema. But the procedure gives a clearer picture of all abnormalities in the large intestine and is unquestionably the most reliable screening test for colon and rectal cancer.

Moreover, if results are normal, it can be performed less frequently. Polyps generally take about five years to develop, and another five years to become cancerous. So normal results from a colonoscopy offers the patient a pretty clean bill of health for the colon for about 10 years. In fact, one study found that individuals with negative findings on colonoscopy–even 20 years previously–had a 74 percent lower risk than those without previous colonoscopy.

Medicare, Medicaid and most private insurers pay for a colonoscopy once every 10 years for persons who qualify. Deep in her heart, Pam knows it is the right thing to do.