Colon cancer is a very common type of cancer in the United States. About 1 in 21 men will develop this cancer in their lifetimes, while 1 in 23 women will. Here are four things you need to know about colon cancer.

What are the symptoms of colon cancer?

In the early stages, colon cancer doesn't always cause symptoms. Once the cancer becomes more advanced, you may notice changes in your bowel habits. For example, you may notice that you have diarrhea or constipation for an extended period of time or that you have blood in your stool. You may also feel like you can't empty your bowel completely. Persistent gas or stomach cramps can also be a sign of colon cancer. If you notice these signs, see your doctor to be screened for colon cancer.

How can you be screened for colon cancer?

There are multiple diagnostic tests that can screen you for colon cancer, including fecal occult blood tests and colonoscopies.

A fecal occult blood test can also be used to screen for colon cancer. You can buy a kit for this test at your local pharmacy and take the test at home. Simply place a stool sample inside the provided container and give the container to your doctor. Your doctor will then have the sample analyzed to see if there's any blood in your stool. If there's blood in your stool, you may have colon cancer. Blood in the stool can also indicate non-cancerous conditions like Crohn's disease or hemorrhoids, so your doctor will need to perform a colonoscopy to confirm the diagnosis.

Colonoscopies let your doctor inspect the inside of your colon and identify abnormal growths (polyps) that could indicate cancer. During a colonoscopy, an endoscope will be inserted into your anus to inspect your colon. If polyps are found, your doctor will thread an instrument through the endoscope to remove them. These polyps can then be biopsied to see if cancerous cells are present. If the polyps are cancerous, additional tests will be required to determine how advanced the cancer is.

How can colon cancer be treated?

If you're diagnosed with colon cancer after a fecal occult blood test or a colonoscopy, a number of treatment options are available to you. If the cancer is caught early, excising the polyps may be the only treatment required.

If the cancer is more advanced, you may need to have part of your colon removed. Your surgeon will preserve as much of your colon as possible. If a large section of your colon needs to be removed, it may not be able to function as it did before, and your waste may not be able to leave your body in the usual way. Your surgeon may need to bring your colon through the front of your abdomen, and your waste will empty into an external bag, known as a colostomy bag.

In severe cases, traditional cancer treatments like chemotherapy or radiation therapy can be used. These treatments can be used if the cancer has spread from your colon to the nearby tissues inside your abdomen.

What is the survival rate for colon cancer?

If colon cancer is diagnosed and treated before it spreads past the lining of the colon, the survival rate is between 80% and 95%. If the cancer spreads past the lining of the colon but not to the lymph nodes, the survival rate drops to 55% to 80%. Once the cancer reaches the lymph nodes, the survival rate is only 40%. To protect yourself, get screened regularly for colon cancer. Telling your doctor about changes in your bowel habits or undergoing a colonoscopy can be embarrassing, but it can save your life.

If you haven't been screened for colon cancer, see your doctor about scheduling a fecal occult blood test or a colonoscopy.