Colonscopy
About the test. Unlike a sigmoidoscopy, which views only the lower portion of your digestive tract, a colonscopy checks almost the entire length of the colon. This examination is considered the best technique for visualising the colon. Colonoscopy is performed by a gastroenterologist who looks for ulcers, obstructions, tumours, polyps, inflammation and other bowel problems during the procedures.
How is it done? In order to clean the bowel and improve viewing, the doctor will give you instructions on fasting, laxatives and enemas for the day or two preceding the procedure. You will be given a mild intravenous sedative that will make you sleepy and relaxed before the doctor snakes a flexible, lighted viewing tube through your anus and along the length of your colon. The procedure is usually painless and takes 30 to 60 minutes. You may be allowed to follow the progress of the scope on a video monitor. If a polyp or suspicious area is found, it can be removed or a small sample taken (biopsied) for later examination. If you are awake during the procedure, you may experience slight cramping but this dissipates soon after the procedure is finished. You will feel tired or groggy for several hours afterwards and a friend will need to escort your home from the hospital. If you experience any fever, bleeding or pain, call your doctor.
How often is it needed? If you have no bowel symptoms and no family history of colon cancer, you should probably have a colonscopy every 5 to 10 years, beginning at age 50, in place of sigmoidoscopy. A colonoscopy is required if polyps, tumours or other abnormal findings are detected via the facial occult blood test, sigmoidoscopy or digital rectal examination (see below).
You'll need this test more often if...
About the examination. The digital rectal examination (DRE) is performed by your doctor to detect any tumours in the rectum, the lower intestine and (if you're a man) the prostate gland.
How is it done? You will be asked to undress and lie on your side, a cloth draped over you for modesty. Your doctor will insert a lubricated, gloved finger into your rectum and gently feel for any lumps or abnormal areas. The examination is quick and generally painless.
How often is it needed? Generally digital rectal examination is performed on anyone with symptoms such as bleeding from the anus or change in bowel habits. Some experts question the effectiveness of this test for colon cancer screening because it does not detect most bowel cancers. The test is, however, a simple means for assessing the health of the rectum and prostate.
You'll need this test more often if...
In the fast-moving world of genetics, scientists are uncovering mutations in genes that cause or contribute to an array of maladies. This is possible because researchers have come decoded the human genome. Each of its 30,000 genes provides coding for specific proteins that make up the building blocks of the skin, hair, brain, heart and myraid other body tissues. Gene products also speed up chemical reactions in the body, aiding digestion of food, the beating of the heart, the firing of nerve signals and countless other processes that help us live, grow and thrive.
When a gene goes awry, a faulty protein is produced. In many cases this will not cause any problems. But sometimes a defect in a single gene leads to a serious ailment, such as cystic fibrosis
or haemophilia. Single gene defects are often easily traced from generation to generation as the defective gene is passed from parent to offspring. Geneticists believe that many illnesses are caused
by multiple gene defects acting in combination with such factors as environmental toxins and poor diet. Unfortunately, very few of the genes responsible for complex ailments, such as cancer, Parkinson's disease and diabetes, have been identified to date and their patterns of inheritance remain hard to decipher.
About the tests. More than 400 genetic tests have been developed for predicting disorders ranging from early-onset Alzheimer's disease and breast cancer to heart disease, sickle-cell anaemia and familial adenomatous polyposis (an inhertied condition that leads to colon cancer). Scientists are also working to uncover genes that contribute to schizophrenia, high cholesterol and other forms of cancer, including leukaemia, melanoma, and cancers of the thyroid, prostate, ovaries and kidneys.
A genetic test can help to confirm the diagnosis of an inherited disease. It can also tell you whether you carry certain genes that put you at higher risk for developing an inherited condition. Having a gene, though, is different from having the illness. If you carry the BRCA1 or BRCA2 gene for breast cancer, for example, you have a greater than 50 percent chance of developing the disease and your doctor will want to monitor you closely you discuss preventive therapies. This gene does not mean you will inevitably develop breast cancer. In fact, the great majority of women who do get breast cancer do not carry either of these genes. Cancer is caused by many variables.
Genetic tests are performed most commonly to detect known inherited diseases such as sickle-cell anaemia and phenylketonuria, which can cause brain damage in newborns. Expectant parents can also screen the foetus for genetic diseases such as Down's syndrome. Gene testing to match genetically similar donors for organ transplants is also common.
How is it done? When getting a genertic test, the doctor or technician usually draws a sample of your blood. Sometimes urine, saliva or other body tissues are taken. The sample is then analysed for genetic mutations. In some cases, family members may also be asked to contribute tissue samples for comparsion. Waiting for test results can sometimes take weeks or months and the tests can be expensive.
Special considerations
About the test. Unlike a sigmoidoscopy, which views only the lower portion of your digestive tract, a colonscopy checks almost the entire length of the colon. This examination is considered the best technique for visualising the colon. Colonoscopy is performed by a gastroenterologist who looks for ulcers, obstructions, tumours, polyps, inflammation and other bowel problems during the procedures.
How is it done? In order to clean the bowel and improve viewing, the doctor will give you instructions on fasting, laxatives and enemas for the day or two preceding the procedure. You will be given a mild intravenous sedative that will make you sleepy and relaxed before the doctor snakes a flexible, lighted viewing tube through your anus and along the length of your colon. The procedure is usually painless and takes 30 to 60 minutes. You may be allowed to follow the progress of the scope on a video monitor. If a polyp or suspicious area is found, it can be removed or a small sample taken (biopsied) for later examination. If you are awake during the procedure, you may experience slight cramping but this dissipates soon after the procedure is finished. You will feel tired or groggy for several hours afterwards and a friend will need to escort your home from the hospital. If you experience any fever, bleeding or pain, call your doctor.
How often is it needed? If you have no bowel symptoms and no family history of colon cancer, you should probably have a colonscopy every 5 to 10 years, beginning at age 50, in place of sigmoidoscopy. A colonoscopy is required if polyps, tumours or other abnormal findings are detected via the facial occult blood test, sigmoidoscopy or digital rectal examination (see below).
You'll need this test more often if...
- You have ongoing inflammatory bowel problems, such as ulcerative colitis or Crohn's disease (Annually).
- You have had colon cancer. (Every one to three years).
- You have had polyps in your bowel. (Every one to three years).
- You have a history of hereditary polyp disease. (Annually beginning as early as age 10).
About the examination. The digital rectal examination (DRE) is performed by your doctor to detect any tumours in the rectum, the lower intestine and (if you're a man) the prostate gland.
How is it done? You will be asked to undress and lie on your side, a cloth draped over you for modesty. Your doctor will insert a lubricated, gloved finger into your rectum and gently feel for any lumps or abnormal areas. The examination is quick and generally painless.
How often is it needed? Generally digital rectal examination is performed on anyone with symptoms such as bleeding from the anus or change in bowel habits. Some experts question the effectiveness of this test for colon cancer screening because it does not detect most bowel cancers. The test is, however, a simple means for assessing the health of the rectum and prostate.
You'll need this test more often if...
- You have had prostate cancer.
- You have had colon cancer.
- You have a strong family history of prostate or colon cancer.
- ALL OF THE ABOVE: a digital rectal examination may be performed earlier than age 50 at your doctor's discretion.
In the fast-moving world of genetics, scientists are uncovering mutations in genes that cause or contribute to an array of maladies. This is possible because researchers have come decoded the human genome. Each of its 30,000 genes provides coding for specific proteins that make up the building blocks of the skin, hair, brain, heart and myraid other body tissues. Gene products also speed up chemical reactions in the body, aiding digestion of food, the beating of the heart, the firing of nerve signals and countless other processes that help us live, grow and thrive.
When a gene goes awry, a faulty protein is produced. In many cases this will not cause any problems. But sometimes a defect in a single gene leads to a serious ailment, such as cystic fibrosis
or haemophilia. Single gene defects are often easily traced from generation to generation as the defective gene is passed from parent to offspring. Geneticists believe that many illnesses are caused
by multiple gene defects acting in combination with such factors as environmental toxins and poor diet. Unfortunately, very few of the genes responsible for complex ailments, such as cancer, Parkinson's disease and diabetes, have been identified to date and their patterns of inheritance remain hard to decipher.
About the tests. More than 400 genetic tests have been developed for predicting disorders ranging from early-onset Alzheimer's disease and breast cancer to heart disease, sickle-cell anaemia and familial adenomatous polyposis (an inhertied condition that leads to colon cancer). Scientists are also working to uncover genes that contribute to schizophrenia, high cholesterol and other forms of cancer, including leukaemia, melanoma, and cancers of the thyroid, prostate, ovaries and kidneys.
A genetic test can help to confirm the diagnosis of an inherited disease. It can also tell you whether you carry certain genes that put you at higher risk for developing an inherited condition. Having a gene, though, is different from having the illness. If you carry the BRCA1 or BRCA2 gene for breast cancer, for example, you have a greater than 50 percent chance of developing the disease and your doctor will want to monitor you closely you discuss preventive therapies. This gene does not mean you will inevitably develop breast cancer. In fact, the great majority of women who do get breast cancer do not carry either of these genes. Cancer is caused by many variables.
Genetic tests are performed most commonly to detect known inherited diseases such as sickle-cell anaemia and phenylketonuria, which can cause brain damage in newborns. Expectant parents can also screen the foetus for genetic diseases such as Down's syndrome. Gene testing to match genetically similar donors for organ transplants is also common.
How is it done? When getting a genertic test, the doctor or technician usually draws a sample of your blood. Sometimes urine, saliva or other body tissues are taken. The sample is then analysed for genetic mutations. In some cases, family members may also be asked to contribute tissue samples for comparsion. Waiting for test results can sometimes take weeks or months and the tests can be expensive.
Special considerations
- If you have a strong family history of a specific disease, such as colon or breast cancer, your doctor may recommend a genetic test. However, learning that your carry a genetic defect can be emotionally trying, especially if no good treatments for the associated condition are currently available. In addition, some ethicists have raised concerns about potential workplace and insurance discrimination. The decision to undergo a genetic test is a very personal one.
- If you are considering testing, it is essential that you first speak with a genetic counsellor who's professionally trained to aid you in decision-making and help you interpret the test results. To learn more, contac the Human Genetics Society of Australasia on (03) 57722779 or at www.hgsa.com.au.
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