The number of deaths in the U.S. from colorectal cancer has been decreasing for decades thanks to preventive screening, but the American Cancer Society (ACS) estimates that more than 100,000 Americans annually continue to be diagnosed with the disease. The ACS recommends people at average risk for colorectal cancer start regular colorectal cancer screening at age 45.

Many people diagnosed with colon cancer have no symptoms at all. However, you should learn the signs and risk factors, says Christian G. Stevoff, MD, Northwestern Medicine gastroenterologist.

"Having a colorectal cancer risk factor doesn't guarantee that you will develop colorectal cancer," says Dr. Stevoff. "And having one of these symptoms also doesn't mean that you have colorectal cancer. But knowing your risks and communicating your symptoms to your physician can be vital in detecting colorectal cancer early."

A colonoscopy is the only recommended screening test for patients with an increased risk of colorectal cancer, due to a family or personal history of colorectal cancer or lifestyle risk factors. High-risk individuals may need to have a colonoscopy performed earlier and more frequently than patients at normal risk, per the discretion of their physician.

Average-risk patients should have a colonoscopy every 10 years, or another screening test, such as a flexible sigmoidoscopy, or a stool-based test, every one to five years, depending on which test is performed. Screening should occur between the ages of 45 and 75. It may be continued until the age of 85 based on health and life expectancy.

These screening guidelines are for patients with no symptoms. If symptoms appear, you should address them with your physician on a case-by-case basis.

When detected early, the five-year survival rate for colorectal cancer is about 90%.