Screening For Colon Cancer.

As noted earlier, the present cure rate for colon cancer could be greatly improved by earlier detection and treatment of the disease. A wide-ranging study by the American Cancer Society concluded that all persons over the age of forty, including those with no symptoms, should have a digital rectal examination annually. This examination is easily performed and, while it may be embarrassing for the patient, it involves no discomfort. The doctor gently inserts a rubber-gloved finger into the rectum. The doctor can then ascertain the smoothness of the rectal wall surface and, in men, the size and characteristics of the prostate. At the time of a digital rectal examination, a stool sample is taken for chemical testing for occult or hidden blood.

There are many types of tests for stool occult blood. Most use slides impregnated with a chemical that is capable of detecting the presence of blood even in microscopic amounts. Patients taking this test should consume a meatless high-fiber diet free of vitamin C for at least forty-eight hours before preparing for the initial part of the test. The actual test consists of taking two separate stool samples on each of three consecutive days. These samples, which are small amounts of feces, are placed on the slide and must be examined within four days. The slide is treated with a drop of developer that is included in the test kit. If a blue color appears, this indicates that there is blood in the stool. This test is inexpensive, simple to do, and gives immediate results. Increasingly, it is recommended as a screening test that should be done on a regular basis among people over the age of forty, or even younger among those who are at a risk of developing colon or rectal cancer.

Men and women who are at a high risk of developing colon or rectal cancer should receive more frequent and intensive examinations beginning at an early age, perhaps as early as age twenty. This group includes persons with familial polyposis (Gardner's syndrome), ulcerative colitis, a history of adenomas or prior large bowel cancer, or a strong family history of colon or rectal cancer. If any abnormalities are found with these simple examinations, the patient may be asked to undergo colonoscopy or a barium enema, an X-ray examination—or even both. Furthermore, as an added precaution, sigmoidoscopy should be performed every three to five years after two initial sigmoidoscopies one year apart are negative (meaning they do not yield any findings of bowel disease).

For information on sigmoidoscopy please see the chapter on sigmoidoscopy.