Image of a cigarette as one way you get colon cancer

How Do You Get Colon Cancer?

Updated December 7, 2023.

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Colorectal cancer is the third most common type of cancer in the United States (if breast and prostate cancer are combined). About 4 percent of people in the U.S. will be diagnosed with colorectal cancer at some point in their lives. Colorectal cancer also makes up about 8.7 percent of all cancer deaths, though the five-year survival rate is approximately 63 percent.

The good news is that there are numerous forms of treatment and therapy to control cancer and manage its symptoms. But how do you get colon cancer in the first place? Read on to learn more.

What Is Colon Cancer?

Colon cancer describes any cancer that begins in the colon, or large intestine. The colon is the last part of the digestive tract, ending at the rectum. Because of this proximity and similar symptoms, colon and rectal cancers are usually referred to collectively as colorectal cancer.

Colon cancer typically starts as a colon polyp, which is a small clump of noncancerous cells forming along the lining of the large intestine. A colon polyp can be easily removed, but left to its own devices, a polyp can potentially turn into a cancerous growth (tumors).

Symptoms of Colon Cancer

Many people who have colon cancer don’t exhibit any noticeable symptoms in the early stages of the disease. As the disease progresses, however, you may experience the following colon cancer symptoms:

  • Persistent change in bowel movements (diarrhea, constipation, other changes to stool consistency)
  • Cramps, bloating, gas, general pain, and other forms of abdominal pain and discomfort
  • Rectal bleeding
  • Blood in your stool
  • Feeling incomplete emptying of your bowels
  • Unexplained weight loss
  • Physical weakness and fatigue

Exact colon cancer symptoms can vary based on the size of the tumor and its location in your large intestine.

What Causes Colon Cancer?

Unlike a cold or flu, colon cancer is not something that you can “catch” from other people. Cancer in general is caused by a mutation in your cells’ DNA. This mutation causes cells to grow out of control, eventually forming into tissue masses known as tumors. As these tumors grow, they can break off and travel through your blood to other areas of the body where they can latch and grow. This is a process known as metastasis. When this is left untreated, the tumors will eventually cut off blood and nutrients to vital organs and tissues.

As of yet, there is no known cause of colon cancer or cancer in general. Research has yet to identify what specifically causes the genetic mutation resulting in cancerous growths, though there is a general agreement that it is likely a mix of heredity, environmental factors, and lifestyle factors.

Risk Factors for Colon Cancer

Some factors in your life can potentially increase your risk of colon cancer. These are known as risk factors, and some of them are things you can change or affect, while others cannot be changed. The latter most commonly include your age and a family history of colon colorectal cancers, but other risk factors include:


Most people associate smoking with lung cancer and heart issues, but research suggests that long-term cigarette smoking may increase your risk of colorectal cancer. Smokers are more likely to have other cancers in general.


Moderate to heavy alcohol use has also been linked to a higher risk of colorectal cancer.


While no singular food or diet will dramatically increase or decrease your risk of colon cancer, studies do show that a high intake of processed meats (like hot dogs, sausages, and deli meats) and red meats (like beef, pork, and lamb) may increase your risk of colon cancer. Low levels of vitamin D may also be a risk factor for colon cancer.

Sedentary Lifestyle

A lack of regular physical activity may greatly increase your risk of developing colon cancer.


Although anyone can get colon cancer at any age, it is far more common in people aged 50 or older. However, cases are rising among people younger than 50, though the exact reason for this is not completely known.

Family History

A majority of colon cancer diagnoses occur in people without a family history of the disease. However, up to 1 in 3 people who do develop colon cancer have family members who have had the disease. This risk is highest among those with a first-degree relative (a parent, sibling, or child). The exact reasons for this are unknown, though it may be a result of inherited genes or shared environmental factors.

Inflammatory Bowel Disease

If you have a history of inflammatory bowel disease (IBD), including Crohn’s disease or ulcerative colitis, you have an increased risk of colon cancer. IBD contributes to inflammation in the colon. Left untreated, this inflammation can potentially progress to dysplasia, which refers to cells in the lining of the colon or rectum that appear abnormal but are not cancerous. Over time, these abnormal cells may turn into cancer.

Type 2 Diabetes

Those with type 2 diabetes are at a higher risk of developing colon cancer.

It’s important to understand that risk factors are not predictors for a patient. You may not have any of the above risk factors, but you can still develop colon cancer. Someone else with several risk factors may never develop colon cancer.

Preventing Colon Cancer

While there is no way to completely prevent any form of cancer, taking the proper steps in your life and health can significantly reduce your risk of developing the disease.


Regular screenings are easily the best way to catch colon cancer early. Screening involves tests that look for cancer or precancerous growths in those who don’t exhibit any symptoms. Most doctors and health care providers recommend regular screenings beginning at age 45.

When abnormal cells develop into polyps, it actually takes a relatively long time (from 10 to 15 years) for them to develop into colon cancer. Regular screening allows doctors to identify and remove polyps before they have a chance to become malignant growths. Alternatively, if these polyps do develop into cancer, regular screening can find cancer early, when it is smaller and more confined and thus easier to treat.

There are a variety of effective screening test options available, including stool tests, colonoscopies, and CT colonography. Talk to your doctor to determine the best option for your needs while still taking into account your personal preferences.


If you already have a high risk of colon cancer, consider reducing or limiting your consumption of red meat and processed meat. Opt for a diet that focuses on lean sources of protein, fruit, vegetables, and whole grains.


Stay active to reduce your sedentary time. Maintain a regular exercise regimen comprising moderate to vigorous activity. The exact amount of exercise will vary from person to person, but most experts recommend about an hour of activity on most days of the week.

Alcohol and Smoking

Limit your alcohol consumption to just one to two drinks per day. If you smoke, consider quitting.

There is no singular way to prevent colon cancer, but with the right steps, you can reduce your risk of colon cancer and prevent it from progressing to more advanced stages. The Everlywell at-home colon cancer screening test features an easy stool sample collection kit to help detect colon cancer early for any given patient (you collect your sample at home and send it into a lab for testing). Once you receive your results, you can talk with your healthcare provider and receive a professional diagnosis and treatment, if necessary.

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