Colon cancer symptoms can be confusing. Common stomach ailments or a change in bowel habits are common occurrences. They don’t always mean that you have a serious condition such as colon cancer. However, not everything should be ignored. Learn about colon cancer symptoms and when it’s a good idea to contact your physician. Common colon cancer symptoms include:

  • Blood in your stool or bleeding from the rectum
  • Unexplained or Unintentional weight loss
  • Anemia
  • Unexplained fatigue
  • Cramping pain in the lower stomach
  • A feeling of discomfort or an urge to have a bowel movement when there is no need to have one
  • Change in bowel habits or blood in the toilet after having a bowel movement
  • Change in the appearance of the stool, or dark / black-colored stools

Let’s take a closer look at these symptoms to determine when you should talk to your doctor about them.


One of the most disturbing symptoms of colon cancer can be bleeding from the rectum or blood in the toilet. Conditions such as hemorrhoids or fissures can also cause small amounts of blood, so if you notice blood, contact your physician and be sure to explain any other symptoms that you may be experiencing at the same time. A large amount of blood may warrant a visit to the emergency room.

Unexplained Fatigue, Weakness, or Weight Loss

Chronic rectal bleeding can cause iron deficiency (anemia). You might feel tired all of the time and have pale skin as a result. If your energy level drops or you begin to lose weight for no reason, take note of when the changes occur and contact your physician for evaluation. Anemia can also be a sign of internal bleeding. Your doctor should investigate the cause.

It is important to remember that most these conditions may have causes other than colon cancer. Fear of a cancer diagnosis shouldn’t keep you away from seeing your health care provider if you are experiencing symptoms. Chances are good that your symptoms can be treated. If cancer is suspected, the earlier the cancer is detected the better off you will be. Nearly 90% of colon cancer is treatable and survivable if diagnosed in its early stages.

Stomach Discomfort or Cramping

Like constipation or diarrhea, stomach discomfort is a common occurrence and can be the result of poor diet, food intolerance, stress or other factors. Be aware of discomfort that does not go away or cramping that gets worse. Additionally, if you have the constant feeling that you need to have a bowel movement and the feeling is not relieved by having one, contact your physician.

Change in Bowel Habits

While it is common for people to experience a change in their bowel habits from time to time, there are some changes that should be evaluated by a physician if they persist. If you notice any of these changes to your bowel habits, take note of when the changes began to occur and any other lifestyle changes may have occurred at the same time. This information will help your physician determine the cause.

  • Diarrhea. Loose stool and diarrhea are common occurrences. The condition can be caused by intolerance to certain foods, medication, stress, or exposure to bacteria (often experienced when traveling). Most people will get at least a mild case of diarrhea several times per year. In most cases, the condition will resolve itself within two to three days. Your health care provider should investigate diarrhea that lasts more than three days.
  • Constipation. Constipation is defined as having less than three bowel movements in a week, and it is one of the most common gastrointestinal complaints. Having constipation, however, does not mean you have colon cancer. A change in your diet, poor nutritional habits, stress, dehydration or lack of physical activity can also cause constipation. Physicians generally recommend that if you have constipation for more than two weeks, you should see your doctor so a cause can be determined.

Change in the Appearance of Stool

The way that your stool looks can be a good indicator of what is going on inside your body. Small, hard stool is an indicator of constipation. But if you notice one of these other changes, contact your physician.

  • Change in Shape. If your stool becomes thin, narrow or ribbon-like this could be an indication of changes inside your colon. Contact your health care provider to have the condition evaluated.
  • Change in Color. If you notice blood in the stool, or darkened stool this could also be an indication of changes inside the colon. Your physician can help you to determine the cause.

Not having any symptoms at all?

Keep in mind, that many people who are diagnosed with colon cancer report having no symptoms prior to their diagnosis. Don’t wait for symptoms to occur to get screened for colon cancer if you are over the age of 50 or if you have a family history of the disease. Talk to your physician or primary care provider to get more information about screening options.


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Information on these pages is provided for educational purposes only. Consult your own physician before making any medical decisions.