Colorectal Cancer

The colon and the rectum—the two parts of the large intestine—are common places for cancer to occur. It is often a hidden cancer because it doesn't usually cause symptoms in its early stages.

Colon cancer affects men and women equally, usually after age 50. That's why experts recommend that adults be tested regularly for colorectal cancer after age 50. Testing is especially important for individuals who are at increased risk for developing colorectal cancer. That include those who: have had polyps (a benign growth in the colon or rectum); have a close family member with colorectal cancer; have ulcerative colitis or Crohn's disease; or who eat a fatty diet or smoke.

Symptoms of colorectal cancer include:

  • diarrhea or constipation
  • a feeling that the bowel isn't emptying completely
  • blood in the stool
  • stools that are narrower than usual
  • frequently feeling full or bloated
  • weight loss with no known reason

There are several ways to check for hidden colorectal cancer. The most effective test is the colonoscopy. In this test, a thin, flexible tube with a camera on the end is passed through the anus and up through the rectum and colon. Any precancerous polyps can be removed during the test. A sigmoidoscopy uses a similar tube, but it is able to look into only the lower portion of the colon. A third test, the fecal occult stool test, can be done at home. It checks for blood in the stool, which can be a sign of bleeding from a colorectal polyp or cancer.


Treatments for colorectal cancer include surgery, chemotherapy, radiation, or a combination of these.

Colorectal Cancer Articles

Ask the doctor: Aspirin and cancer prevention

Taking aspirin regularly may reduce risk of colon cancer but also increases risk of internal bleeding. It is not possible yet to routinely determine who would be helped more than harmed by taking aspirin for colon cancer prevention. (Locked) More »

Do older adults need colorectal cancer screenings?

Whether older adults should get routine colorectal cancer (CRC) screenings is debated. Some guidelines suggest that people should not get screenings past age 75 or 80. Some evidence shows the screenings are effective well into the 80s in previously unscreened patients with no other chronic conditions. For people older than 75, it’s best to weigh the risks and benefits of screening. A family history of CRC or precancerous polyps increase the risk for CRC and may be cause for a screening.  (Locked) More »

Ask the doctor: Is your cancer risk genetic?

If a first-degree relative—a parent, sibling, or child—has developed certain cancers, then one’s own risk of getting the cancer is greater than the average person’s. However, it does not mean that one would definitely get the cancer. (Locked) More »

5 simple steps that may help prevent colorectal cancer

There is no guaranteed way to prevent colorectal cancer. However, some steps may help. Screenings, such as a colonoscopy, can help find cancerous and precancerous tumors. A daily aspirin may reduce the risk for developing colorectal cancer by 20%. People with a blood vitamin D level greater than 30 ng/ml experience a lower risk of colorectal cancer. Eating red meat and drinking alcohol may increase the risk of colorectal cancer. Exercising may reduce the risk of colorectal cancer. More »

How to prevent colorectal cancer

Beyond getting regular colon cancer screening, there are several things women can do to reduce their risk of getting colon cancer. Lifestyle strategies should focus on eating less red meat, exercising more, and taking vitamin D and calcium when appropriate. More »

Best way to prevent advanced colon cancer

A colonoscopy can help prevent the diagnosis of late-stage colon cancer. Research suggests that the test can reduce the likelihood of advanced colorectal cancer diagnosis by 70% in adults with average risk. (Locked) More »

Colorectal cancer genes identified

A huge new study has identified many new genetic changes that appear to be involved in causing colorectal cancer. Each of these newly identified genetic changes is a target for drug therapy. (Locked) More »

Making smart screening decisions: Colon cancer screening

Colorectal cancer is the third most common cancer among men and women. Several tests can find hidden colorectal cancer while it is still small and treatable. These include colonoscopy, flexible sigmoidoscopy, CT colonography, fecal occult blood test, and others. Testing should generally start at age 50, but women (and men) with a strong family history of colorectal cancer should talk with their doctors about having their first colonoscopy sooner than that. It's best to have a colonoscopy once every 10 years; a virtual colonoscopy, flexible sigmoidoscopy, or double-contrast barium enema once every five years; or a stool check for blood once a year. (Locked) More »