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Understanding Colon Cancer: Symptoms, Causes, and Diagnosis

Colon cancer, also known as colorectal cancer, is a widely recognized form of cancer that affects the large intestine, which is the lower part of the digestive system. With its prevalence and potentially serious consequences, understanding the ins and outs of colon cancer is essential for everyone.


What is Colon Cancer?

Colon cancer begins as small, noncancerous clumps of cells called polyps, which over time can turn into cancer. These polyps can be small and produce few, if any, symptoms. For this reason, doctors recommend regular screening tests to help prevent colon cancer by identifying and removing polyps before they become cancerous.

What are the Symptoms of Colon Cancer?

Early on, most people with colon cancer don't have symptoms. When symptoms do appear, they can vary depending on the cancer's size and location in the large intestine. The common symptoms include:

  • A persistent change in bowel habits, including diarrhea or constipation or a change in the consistency of your stool
  • Rectal bleeding or blood in your stool
  • Persistent abdominal discomfort, such as cramps, gas, or pain
  • Weakness or fatigue
  • Unexplained weight loss

These symptoms can be caused by conditions other than cancer, but it's important to have them checked by a doctor to determine the cause.

Who is Affected by Colon Cancer?

Colon cancer can strike men and women at any age, although the risks increase after the age of 50. Those with a family history of colon cancer or a personal history of ulcerative colitis or Crohn's disease may have an increased risk. It's also suggested that individuals with certain genetic syndromes have an increased risk of colon cancer.

Screening vs Diagnosis

Screening tests are typically done when you don't have symptoms, aiming to detect colon cancer at an early stage when treatment is most likely to be effective. Diagnostic tests are used when a person has symptoms or when a screening test result suggests that cancer might be present. Several commonly used screening tests and diagnostic tests include colonoscopy, fecal immunochemical test, and digital rectal exam.

Colon Cancer Causes and Risk Factors

The risk for colon cancer is multifactorial, influenced by genetics, diet, lifestyle, and certain health conditions. Some known risk factors for colon cancer include:

Age: More than 90% of colon cancers are diagnosed in individuals over 50.

Personal or Family History: If you or a close relative have had colon cancer or polyps, your risk of developing the disease may be higher.

Inflammatory Intestinal Conditions: Long-standing inflammation in the colon, such as ulcerative colitis or Crohn's disease, can increase your risk.

Lifestyle Factors: Such as sedentary lifestyle, a low-fiber, and high-fat diet, heavy alcohol consumption, and tobacco use.

Diabetes: A diagnosis of diabetes or insulin resistance.

Understanding these risk factors can help in assessing an individual's risk and taking steps to lower it.

How is Colon Cancer Diagnosed?

Early diagnosis of colon cancer can greatly increase the chances of successful treatment and recovery. The gold standard for diagnosis is a colonoscopy, a test that allows the doctor to look at the inner lining of the colon.

Colonoscopy Procedure

During a colonoscopy, a long, flexible tube (colonoscope) is inserted into the rectum. It contains a tiny video camera at the tip. The patient is typically sedated for comfort during the procedure. The doctor can then view images of the colon on a monitor. If polyps are found, they can be removed and tested for cancer during the same procedure.

Other Diagnostic Tests

If a colonoscopy indicates cancer, the doctor may order further testing to determine the extent (stage) of the cancer. This might include imaging tests such as CT scan, MRI, PET scan, Chest x-rays, or blood tests.


Colon cancer is a serious and potentially fatal disease, but with early detection and proper treatment, many people can be cured. By knowing the risk factors, recognizing the symptoms, and undergoing regular screenings, individuals can significantly reduce their risk. Those diagnosed with colon cancer have several treatment options, including surgery, chemotherapy, and radiation therapy. It's crucial to talk with your doctor about the best treatment for you and develop a plan that fits your specific medical needs and personal preferences.