Colon Cancer – Warning Signs, Symptoms & Testing

Colon Cancer

Colon cancer is a form of cancer that starts in the large intestines. It may also be referred to as colorectal cancer if it’s present in both the colon and the rectum. This form of cancer can take up to 10 years to develop. It starts as precancerous polyps and progress to cancer. Some of the treatment options for this type of cancer include surgery, chemotherapy, radiation therapy, immunotherapy, and targeted therapy.

Stages of Colon Cancer

Cancer of the colon develops in several stages. The specific stage denotes the size of the tumors and how far cancer has spread. The following are the main stages:

  • Stage 0: This stage is also referred to as the carcinoma in situ. It’s the earliest stage of the cancer. At this point, the cancer has not advanced beyond the inner layer of the colon, and it’s easy to treat.
  • Stage 1: At this stage, the cancerous growth has progressed to the adjacent tissue, but it’s yet to spread to the lymph nodes or other organs.
  • Stage 3: cancer has advanced to the outer layers of the colon, including one to three lymph nodes. Still, it hasn’t spread to distant organs.
  • Stage 4: Cancer at this point has spread to distant sites, including various organs in the body.

colon cancer signs and symptomsEarly Warning Signs

Although most individuals with these signs may not have cancer, it’s crucial to visit your doctor for a conclusive diagnosis. Some of the early signs of this type of cancer include:

  • Fatigue and weakness
  • Abdominal pain
  • Unexplained weight loss
  • Bowel movement feeling without results
  • Rectal bleeding
  • Persistent changes in bowel habits lasting


The signs and symptoms of this type of cancer are not specific. This means they may be present due to other infections or health conditions in the body. Interestingly if cancer of the colon is detected in early stages, it may be asymptomatic. Some of the symptoms that may suggest you have cancer growing in your colon include:

  • Dark-colored stool
  • Narrow stool
  • Inability to empty bowel
  • Blood in stool or rectal bleeding
  • Diarrhea
  • Relentless abdominal discomforts such as gas, cramps or pain
  • Change in bowel habits

Colorectal Cancer

Testing for Colon Cancer

Early diagnosis of colon cancer is the best opportunity of curing the condition. Besides regular tests, your doctor may also conduct a rectal exam and physical examination. They will also ask for details about your family history. The following tests are done to diagnose cancer of the colon.

Blood testing

The doctor will conduct several blood tests to rule out other conditions. Such tests comprise a complete blood count test and liver function tests. They may also screen you for colon cancer via the carcinoembryonic antigen (CEA) test. CEA is a substance produced by cancerous colon cells.


A colonoscopy involves an examination of your colon via a long tube with a camera. The doctor may extract some tissue from the colon for laboratory examination during the procedure.


Your doctor can also request an X-ray to aid in the diagnosis.

PET and CT Scan

A PET scan establishes if specific cells are utilizing glucose than others. This test is ordered alongside a CT scan to provide a detailed image of your colon. The CT scan is also referred to as virtual colonoscopy.



Colorectal Cancer Alliance 

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