It’s a detail a baby boomer must not overlook. As you approach middle age, it’s time to have a frank discussion with your primary care physician about colorectal cancer.

It’s a tricky cancer; in the early stages you may be symptom free. You could be feeling as strong as a horse, but inside your large intestine, little growths, called polyps, could be making the dangerous transition from benign to malignant.

To date, the best tool doctors have in diagnosing this disease is the colonoscopy. The very word strikes fear in the toughest men. Men and women will postpone the procedure because they don’t like the idea of a flexible tube running through their lower pipes. But screening is vital. Dr. David Lieberman, chief of the Division of Gastroenterology and Hepatology at Oregon Health and Science University in Portland, Oregon, says the exciting thing about colon cancer screening “is that, unlike other forms of screening where the goal is to detect early forms of cancer, with colon cancer we can actually prevent it because there is this pre-cancer phase of polyps.”

People of average risk should begin screening at age 50. “However, for individuals who have a close relative, a father, mother, sister or brother with colon cancer, they need to talk to their doctors earlier about colon cancer screening. Many of those patients need to begin screening at age 40,” says Lieberman. It’s good to get screened before you have any symptoms because “we know from various studies that if we wait for symptoms, often the cancers are discovered at a later stage and they’re much more difficult to treat.” Symptoms can include rectal bleeding (bleeding in stools), and changes in bowel habits.

While the colonoscopy is considered the “gold standard,” there are a couple of other screening tools. Lieberman says the fecal occult blood test “is a reasonably good test for detecting cancer, but it’s not going to detect pre-cancerous polyps.” The blood test has to be repeated every year. The sigmoidoscopy, like the colonoscopy, can detect polyps and cancers. The sigmoidoscopy can be performed in an office setting without sedation. “The problem with the sigmoidoscopy is that you’re only looking at the lower part of the colon, so if you happen to have growths further up in the colon, they can be missed.” Lieberman says use of the sigmoidoscopy has dropped off in the United States. For those with a family history of colon cancer, the colonoscopy is the recommended test.

During a colonoscopy, Lieberman says “we use a long, flexible tube with a light on the end of it and a little camera in it that we pass through the entire colon.” If you’re worried about pain or discomfort, Lieberman adds, “When we perform these procedures in the United States, everybody receives sedation. Most patients don’t remember the procedure. What they do remember is the day before the procedure…getting ready.”

The day before the colonoscopy is a day you’ll probably remember for years to come. You’ll be limited to a diet of clear liquids. You’ll also be given a solution that will cause you to visit the bathroom MANY times the evening before. The idea is to clean the colon so your doctor can easily spot and remove polyps. The important thing to remember is to follow your doctor’s prep list to the letter.

If you’re polyp-free after a colonoscopy, Lieberman says you won’t need to repeat the procedure for about ten years. If a benign polyp is found, a repeat colonoscopy is needed sooner, depending on the appearance and size of the polyp.

Does lifestyle have anything to do with developing colon cancer? Lieberman says, “There are lots of studies, and I’ve done some of them, which show that there are some risk factors that seem to be associated with a higher risk of developing colon cancer.” These include diets high in animal fat and low in fiber, diets low in calcium, obesity, smoking and low levels of physical activity. Lieberman cautions that if you start eating healthier food, including fruits, vegetables and whole grain bread, you still need to get screened.

Patients should be encouraged to get screened. Lieberman says he gives a lot of lectures to fellow doctors. “One of the things we emphasize is that it’s important to have this discussion with patients because this is one of the most preventable forms of cancer that we know of, because we can detect these polyps and take them out before there is cancer.” That, says Lieberman, is an exciting opportunity.