Colon (Colorectal) Cancer Symptoms, Facts, Treatment And Prevention

What we call colon cancer occurs when abnormal cancer cells, also known as polyps, occur in the large intestine. Often talked about with colon cancer is rectal cancer which affects those last few inches of Colorectalthe colon that lead to the anus. Together these types of cancer are referred to as colorectal cancers.

By knowing and understanding more about the colon you will be more prepared to observe the symptoms of colon cancer.

Understanding the anatomy of the intestine, using the photo below, will help you understand what symptoms to look for.


Anatomy Of The Intestine

Colon Cancer Overview

In order to have a better understanding of colon cancer symptoms and prognosis, it is best to understand some key facts about colon cancer.

  • Colorectal cancer is the number 3 leading cause of cancer in American men
  • Removing colon polyps can prevent colon cancer
  • Early stages of colon and rectal cancers often present with no symptoms
  • Observing signs and symptoms of colon cancer provide the best path for successful treatment.


In the early stages of colon cancer you may not experience any symptoms but as the cancer grows and progresses, observable changes will occur. Common signs and symptoms you should look for are:

  • Noticeable change in bowel movements. You may experience more or less movements or have diarrhea or constipation. You will also notice a change in the consistency of your stool.
  • Bleeding in your stool or rectal bleeding.
  • Feeling that you have an incomplete bowel movement
  • Stool that is bright red or dark red
  • Constant discomfort in your abdominal region including pain, gas or stomach cramps
  • Chronic fatigue and a general feeling of weakness.
  • Loss of appetite
  • Unexplained weight loss
  • Vomiting
  • Stool that is long and thin, or “pencil-like”

As you can see these symptoms of colon cancer can be easily chalked up to other illnesses, however if you notice any of these symptoms or they worsen over time, make an appointment with your doctor right away. These signs could be a sign of a general bowel discomfort however they could be signs of colon cancer.


So many people tend to ignore signs their bodies send out to alert them to illness or disease, which is why so many types of cancers are not diagnosed until it has progressed beyond the point of a simple treatment. Here are a few facts to help you understand why it is so important to schedule regular visits with your doctor and take note of any strange symptoms you exhibit:

  • More than 100,000 people were diagnosed with colon cancer in 2012 in the U.S.,
  • More than 40,000 were diagnosed with rectal cancer.
  • 1 in 20 Americans will develop colon or rectal cancer.
  • Early detection has greatly reduced the number of deaths from colon cancer.
  • Nearly 40% of colon cancer is found when it is still confined to the colon.
  • Countries with a high fat intake also have high rates of colon cancer
  • The majority of colon cancer cases occur in individuals over 50 years of age.
  • Those of Jewish and African descent are at a higher risk for colon cancer.


Unlike many types of cancer for which there are only risk factors, there are certain habits that have been known to cause colon cancer. Contrary to some myths out there, colon cancer is not contagious.

Some factors that contribute to an increased risk of colon cancer include a family history of colon or rectal cancer and polyps, a diet high in fat and inflammatory bowel diseases such as chronic ulcerative colitis.

Precancerous polyps usually indicate the start of colon cancer. When these cells grow abnormally fast and they don’t diet out, the polyps have progressed from pre-cancerous to cancer cells.

More than a family history of colon cancer, inherited gene mutations also play a role in your risk for developing cancer. Although these gene mutations are no guarantee that one will develop colon cancer, they do increase your risk, which means you may need more frequent colon cancer screenings.

When To Seek Medical Care

You should get in to see your doctor right away if you experience one or more colon cancer symptoms for more than a few days. Often patients ignore symptoms or put off a visit to the doctor in hopes the symptoms will dissipate. If any of these above symptoms persist for more than a few days or worsen, you need to seek medical care.

Colon cancer screenings are effective for detecting the presence of cancer cells in the colon, and early detection will greatly improve your prognosis.

What Tests Can Be Done To Detect Colon Cancer?

If you have been exhibiting symptoms of colon cancer or your doctor suspects that you may have colon cancer there are several tests that may be ordered to confirm a colon cancer diagnosis or another colon-related disease or illness. These tests may be used confirm the presence of cancer cells or to locate the cancerous tumor.

A stool test is one of the earliest done to detect colon cancer. During your yearly visit to the doctor you may be required to provide a fecal sample to test for blood in the stool, which is an early symptom of this type of cancer.

Another test that highlights tumors or other irregularities in the large intestine is the barium x-ray. During this procedure you will be given an enema that contains barium, which allows the x-ray to clearly show any abnormalities in your large intestines.

A colonoscopy is used to allow your doctor to view inside your colon. This allows the doctor to search for small polyps that can be removed and tested for cancer. Recently a new colon cancer screening technique has been introduced, a virtual colonoscopy, for patients at risk for colon cancer.

You and your doctor will determine which test is best.


Your colon cancer treatment plan will be determined by how far your cancer has progressed. You may require one or more of the following treatments:

  • Surgery to target the cancerous polyps, the colon or parts of the colon and even blockages of the colon. Surgery to relieve colon blockage is not intended to cure or kill cancer cells but instead to alleviate symptoms of colon cancer.
  • Radiation Therapy is used to target cancerous polyps to shrink them before surgery or to kill cancer cells that remain after you have already undergone surgery. In some instances radiation therapy is used to ease pain or bleeding or other symptoms.
  • Chemotherapy is a combination of drugs that kill cancer cells. Chemotherapy may be used for the same reasons as radiation therapy or in conjunction with radiation therapy. Because of the side effects associated with chemotherapy you should speak with your doctor about post treatment care.

Next Steps

Once you have been treated for colon cancer it is important to keep appointments for follow up exams. These exams allow for early detection in the event that the cancer comes back. Even after a successful colon cancer treatment survivors are still at risk of the cancer returning for as many as 10 years from the initial diagnosis. Of course the risk is highest in the few years after treatment, the risk remains for quite some time.

You may be asked to attend regular appointments every 3 months during the first years after your treatment. These visits will decrease over time but regular visits will still be necessary to monitor the previously infected area.


One of the best ways to prevent colon cancer is to enjoy a low fat diet that is high in vegetables and other foods high in fiber. Since we know that nations with high colon cancer rates also have high fat diets, we know that high fiber, low fat diets can counteract the carcinogenic-producing fats found in a high fat diet.

Getting pre-cancerous polyps and non-polypoid lesions removed before they develop into cancerous cells is a key component to preventing colon cancer.

A rectal examination and blood test is another effective method for colon cancer prevention. The doctor will perform a digital exam, feeling for abnormal cell growth as a first step. During this same visit you will likely be asked for a stool sample to test for traces of blood and other signs of colon cancer.


During the last twenty years the rate of death due to colon cancer has been steadily declining. This is thanks, in part, to additional colon cancer screenings that allow for early detection. The earlier the pre-cancerous polyps or cancer cells are identified, the better prognosis. Improved treatments and after-care have also contributed to a better colon cancer prognosis.

The most recent colon cancer survival rates are very good, particularly in the early stages. During the in situ stage of colon cancer the survival rate over 5 years is well over 90%. During the local stage (stage II) when the cancer is still in the colon, the 5 year rate of survival is 90%. The regional stage (stage III), where the cancer has begun to grow past the colon and rectum, is 70%. During the distant stage (stage IV) when cancer has spread to the nearby lymph nodes has a 5 year survival rate of just 12%.

Written By Charles Howard

Charles Stanton Howard, MD, is a specialist in Molecular Pathology from the USA. Dr Howard’s educational background includes a BA with the Highest Distinction from the University of Texas, one of the most highly regarded cancer institutes in the world, as well as an MD gained at the University of Virginia.


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