Early Signs of Colon Cancer



For many people, being diagnosed with colon cancer can come as a great shock. Colon cancer patients often claim to feel completely normal at time of diagnosis, so being presented with the knowledge that they have cancer is unsettling to say the least. Colon cancer can develop painlessly and without symptoms. This is not the case with everyone, however.  Here are some of the most common symptoms of colon cancer.


Tumors are often associated with bleeding because, at the beginning stages of growth, their blood vessels are fragile. As a tumor develops, it becomes more invasive and may grow into a nearby blood vessel and cause bleeding. A cancerous polyp may bleed only a small amount of blood that is not even visible to the eye. As the polyp grows into a tumor, there may be evidence of blood in the stool or rectal bleeding.


Anemia is a shortage of red blood cells, the cells that carry oxygen to all areas of the body. An intestinal bleed can cause anemia, with side effects of tiredness and sluggishness. Because the lethargy is associated with a lack of oxygenated red blood cells and not a lack of sleep, additional rest will not help. Severe anemia can cause light-headedness and even fainting.

Abdominal pain or cramping

As the colon tumor grows, it can create an obstruction in the bowel. If the tumor grows large enough to make a blockage, it can also cause nausea and vomiting.

Change in bowel habits

If the tumor is creating an obstruction in the bowel, there may be a change in the appearance or frequency of the stool. Colon cancer is often associated with thin, pencil-like stools and with bouts of constipation or diarrhea. The stool can also appear black or tarry, due to the internal bleeding from the growth (Source: Patient).

If you are experiencing any of these symptoms, call your doctor and make an appointment. Colon cancer is highly treatable when diagnosed in the early stages, and it is preventable with regular colonoscopies. Knowing the symptoms of colon cancer and scheduling routine screenings is the best defense against colon cancer.