Cancer of the Colon and Rectum

The colon and rectum are common sites of cancer. It is estimated that there will be about 140,000 new cases annually in the US and about 55,000 deaths. Screening tests for colon cancer include using tests to find the presence of blood in the bowel movement. These tests are called fecal occult blood tests. Doctors may also use an instrument—the flexible sigmoidoscope—to examine the lower parts of the bowel (where cancers are most commonly found) directly.

• It is suggested that tests to look for blood in the bowel movement should be conducted annually in everyone over age 50 years. If there is a strong family history of colon cancer, then not only should testing be started much earlier, in the 30s or 40s, but testing may need to be more invasive. The doctor can take a small sample of stool and test it in the office. Sometimes it is easier for you to provide a sample or samples at home using a test kit and mailing the samples to your doctor for testing.
  
  
• For more invasive screening, a colonoscopy is performed. This test uses a long narrow flexible tube to view the inside of the bowel. Talk with your doctor about the use of this test because the doctor will take all factors into account (for example, your family history and past medical history) to determine when you need it.

• Your doctor may require you to use a strong laxative (called a bowel cleanser) to clear your bowel of fecal contents before colonoscopy. Several medications are available for bowel cleansing, including polyethylene glycol 3350 (GoLYTELY, NuLYTELY), magnesium citrate (Citroma), and senna (X-Prep). These medications produce diarrhea, which can be uncomfortable, but unless the bowel is empty of stool, the test can be limited and may need to be repeated at a later date. Your doctor may also require a special diet, such as a clear liquid diet, starting 1-2 days before your scheduled colonoscopy.