Symptoms of Colon Cancer


Many cases of colorectal cancer have no symptoms or warning signs until the cancer has advanced. However, the following symptoms may indicate colon cancer. Of course, other conditions can cause the same symptoms, such as hemorrhoids, inflammatory bowel disease (IBD), infection, etc., so be sure to consult your provider if you experience any of the following symptoms.


Abdominal Pain

Almost everyone experiences abdominal pain, bloating or cramps at some point in their life. Most of the time, abdominal pain is not caused by a serious condition, and the severity of the pain does not necessarily reflect the seriousness of the condition causing the pain. However, if you experience any amount of abdominal pain that is unfamiliar, you should talk with your healthcare provider. Your provider may have a simple solution to your pain or may recommend further testing to diagnose the cause of your pain. Pay attention to your body and seek medical care if something doesn’t feel quite right.

Blood in Stool

If you have blood in your stool, you should see your healthcare provider. The provider can help determine whether your symptoms are caused by a condition like hemorrhoids or something more serious, like colon cancer, and can help you decide on the right course of treatment. If you notice either bright red or very dark blood in your stool, along with severe pain, contact your provider as soon as possible. They will be able to examine you and may suggest a colonoscopy to check for polyps or tumors that may be the source of the problem.

Changes in Bowel Habits

Every now and then, we all experience changes in our bowel habits. We may have diarrhea or constipation due to something we ate or the flu. But changes in bowel habits that continue may indicate a more serious condition. If you experience diarrhea or constipation that lasts for more than a few weeks, see your provider.

Other changes in stool that could indicate colon cancer are having narrower than normal stools or unusual changes in the appearance of the stool. If stools are pencil-thin or look different for more than a few weeks, make an appointment with your provider.

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Unexplained Weight Loss

If you lose a significant amount of weight without explanation, you should see your provider. Unexplained weight loss due to colon cancer may not occur until the cancer is in its advanced stages. One of the other symptoms of colon cancer is diarrhea that lasts for more than a few days. Diarrhea can also cause weight loss. If you have lost a significant amount of weight accompanied with other symptoms, talk with your provider as soon as possible to determine the cause.

Unexplained Anemia

Anemia refers to a lowering of red blood cell count. In terms of colon cancer, anemia may be caused by a microscopic amount of chronic blood loss in the stool. In this case, iron is lost along with red blood cells and can slowly deplete the total body stores of iron. The production of new red blood cells is reduced and eventually the total red blood cell count decreases, causing anemia. Anemia can also cause fatigue because red blood cells deliver oxygen to the body’s tissues. In women, iron deficiency is common during menstruation. However, for men, iron deficiency is uncommon and needs to be further investigated by a healthcare provider.


Vomiting can be caused by a number of normal occurrences: motion sickness, a virus, or unpleasant sights or smells. If nausea and vomiting are accompanied by other symptoms, however, such as constipation or pain, colon cancer could be the cause. When vomiting is a symptom of colon cancer, it is usually because a tumor is causing a bowel obstruction. Depending on the severity of the blockage, solids, liquids and even gases may be prevented from passing through the colon. This can lead to painful stomach cramps and constipation. Either of these symptoms can result in nausea and vomiting.

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