Take the Quiz: Colorectal Cancer

Even though we don't know the exact cause of most colorectal cancers, we do know it’s possible to prevent many colorectal cancers.

Regular colorectal cancer screening is one of the most powerful tools for preventing colorectal cancer. Screening is the process of looking for cancer or pre-cancer in people who have no symptoms of the disease.

Regular screening can help prevent colorectal cancer by finding abnormal colon growths (called polyps) so they can be removed before they have a chance to turn into cancer.

You can also lower your risk of developing colorectal cancer by managing risk factors that you can control, like diet, weight, and physical activity.

Colorectal cancer is the third most common cancer diagnosed in the United States (excluding skin cancers).

It’s important to get screened for colorectal cancer even if you feel OK. Testing before you feel bad can help prevent the disease or find it early, when it’s easier to treat.

Most people with early colorectal cancer don’t have symptoms. But if you have any of the following, see a health care provider:

• A change in bowel habits, such as diarrhea, constipation, or narrowing of the stool, that lasts for more than a few days
• A feeling that you need to have a bowel movement that’s not relieved by doing so
• Rectal bleeding, dark stools, or blood in the stool (often, though, the stool can look normal)
• Cramping or belly pain
• Weakness and extreme tiredness that doesn’t get better with rest
• Unexplained weight loss

Most of these symptoms are more often caused by other conditions, such as infection, hemorrhoids, irritable bowel syndrome, or inflammatory bowel disease, not colorectal cancer. Still, if you have any of these problems, it’s important to see a health care provider right away so the cause can be found and treated, if needed.

Colorectal cancer has been linked to the use of alcohol. It is best not to drink alcohol. If people do drink, they should have no more than 2 drinks a day for men and 1 drink a day for women.

If you are not physically active, you have a greater chance of developing colorectal cancer. Moderate to vigorous physical activity can help reduce your risk.

People who have smoked for a long time are more likely than people who don't smoke to develop and die from colorectal cancer. If you use any form of tobacco, stop! We can help.

Diet choices can also impact colorectal cancer risk. A diet that’s high in red meats (such as beef, lamb, or liver) and processed meats (hot dogs and some luncheon meats) can increase risk. 

Cooking meats at very high temperatures (frying, broiling, or grilling) creates chemicals that might increase cancer risk, too, but it's not clear how much this might contribute to an increase in colorectal cancer risk.

Diets high in vegetables, fruits, and whole grains, and that limit or avoid red and processed meats and sugary drinks, probably lowers risk of colorectal cancer.

See the American Cancer Society guideline for diet and physical activity for cancer prevention. 

For people at average risk of colon and rectal cancer, the American Cancer Society recommends starting regular screening at age 45. People older than 75 should talk with their health care provider about whether continuing screening is right for them.

If you are at high risk of colon or rectum cancer based on family history or other factors, you may need to start testing before age 45. Talk to a health care provider about your risk for colorectal cancer to know when you should start testing.

There are many tests that can look for colorectal cancer. Screening can be done either with a sensitive test that looks for signs of cancer in a person’s stool (a stool-based test), or with an exam that looks at the colon and rectum (a visual exam).

Stool-based tests

• Yearly fecal immunochemical test (FIT) *, or
• Yearly guaiac-based fecal occult blood test (gFOBT) *, or
• Multi-targeted stool DNA test (MT-sDNA) every 3 years*

Visual (structural) exams of the colon and rectum

• Colonoscopy every 10 years, or
• CT colonography (virtual colonoscopy) every 5 years*, or
• Flexible sigmoidoscopy every 5 years*

*If a person chooses to be screened with a test other than colonoscopy, any abnormal test result should be followed up with colonoscopy.