American Medical Association Family Medical Guide - American Medical Association [107]
Fecal Occult Blood Test
Blood in the stool can be an early sign of cancer of the colon or rectum but also of less serious conditions such as hemorrhoids. A screening test for colon cancer, called the fecal occult blood test, detects the presence of hidden blood in the stool. Because small tumors in early stages may bleed infrequently and in tiny amounts, the blood is impossible to see with the naked eye and can be detected only with a chemical test. Most fecal occult blood tests are performed at home, but doctors also often take a stool sample with a gloved finger during a routine pelvic examination or rectal examination. Doctors recommend that everyone have a fecal occult blood test every year starting at age 50. People who have risk factors for colon cancer, such as a family history of colon cancer or having previous colon polyps, should start having annual tests at age 40.
Your doctor may give you a testing kit to use at home. For this test (called the guaiac smear test), you take small samples of stool from three different bowel movements and place them on a special card. You mail the card to your doctor’s office or to a laboratory, where the samples are tested for the presence of blood.
You can get a flushable reagent stool blood test from a pharmacy without a prescription. For this test, you place a chemically treated tissue in the toilet after a bowel movement. You look for a change of color in the tissue and note it on the card provided with the kit. You repeat the procedure for two or more bowel movements and then mail the results to your doctor.
With either kit, follow the instructions carefully. Before taking the test, you will be asked to make some changes in your diet and to avoid some medications that could affect the test results. For example, you will be asked not to take aspirin and other nonsteroidal anti-inflammatory drugs for 7 days before the test. (It is OK to take acetaminophen because it doesn’t increase bleeding.) For 3 days before the test, don’t consume more than 250 milligrams a day of vitamin C (in food or supplements) or eat red meat or raw broccoli, cauliflower, horseradish, parsnips, radishes, turnips, or melons. Don’t perform the test during or for 3 days after your menstrual period, if you have hemorrhoids that are bleeding, or if you have blood in your urine. Avoid using toilet bowl cleaners for several days before the test because they can affect test results. Protect the card on which you put the stool samples from heat, light, and chemicals (such as iodine, bleach, and household cleaners).
Recommended Screening Tests
The following table lists frequently performed screening tests, how often people of average risk should have the tests, and at what age the tests should be performed. These are general guidelines. Depending on your health, your health risks, your family health history, and your health history, your doctor may recommend that you have some of these tests more frequently or less frequently.
Age Group Test When to Have the Test
Adults younger than 30 Physical examination (including blood pressure measurement) Every 1 or 2 years, or as often as your doctor recommends.
Dental examination Every 6 months.
Eye examination Once between ages 20 and 29.
Pelvic examination Once a year, starting at age 18.
Pap smear Once a year for sexually active women, or as often as your doctor recommends; every 6 months if you have more than one sex partner.
Cholesterol test Not needed unless you are at increased risk of heart disease because of smoking, obesity, high blood pressure, diabetes, or a family history of heart disease; if you’re at increased risk, have a baseline test at age 20 and every 5 years if last test result was normal.
Ages 30 to 39 Physical examination (including blood pressure measurement) Every 1 or 2 years, or as often as your doctor recommends.
Dental examination Every 6 months.
Eye examination Once