Colon Cancer | Symptoms and Risk Factors | MedStar Health

MedStar Health is committed to helping you prevent colon cancer through routine screening because when found early, it is 90% curable.

From prevention and screening to diagnosis to treatment, we use advanced technology to understand what’s going on with your disease. This allows our team of experts to design a precise treatment plan to eliminate your cancer and prevent it from returning.

Also known as colorectal cancer when grouped with rectal cancer, colon cancer begins as a mass of cells, or tumor, that develops in the colon. The colon is part of the digestive system where it absorbs food and water and stores waste.

More than 130,000 people in the U.S. are diagnosed with this cancer every year. Many times, people don’t know they have this cancer because there are no symptoms in early stages. When symptoms do appear, it can be more difficult to cure than when it’s found early through routine screening.

With routine screening via colonoscopy, your doctor can remove or treat precancerous growths and identify cancer early when it’s easier to cure.


image of a person holding an anatomical model of the digestive tract

Colon cancer occurs in the last two parts of the digestive system: the colon (large intestine) or rectum (connects the colon and the anus). Most occurrences begin as small abnormal growths of tissue called polyps that form in these areas of the digestive system. A polyp is not cancer, but it can change over time into cancer.

By knowing the symptoms and taking preventative steps through screening, colon cancer is beatable when caught early.

Symptoms may include:

  • Diarrhea, constipation, or the feeling that the bowel has not emptied
  • Unusually narrow stools
  • A bloody stool
  • Bloating, cramping, fullness, and/or frequent gas pains
  • Unexplained weight loss
  • Continuous fatigue
  • Vomiting

If you experience symptoms for more than two weeks, see your doctor. These symptoms can also be caused by other conditions, so it's important to consult with your MedStar Health doctor to determine whether they are connected to colon cancer or some other condition.

Individuals with colon polyps or cancer may have no symptoms at all, especially at first. By the time most symptoms appear, the cancer is already growing, making it harder to treat. It is important to get screened, pay attention to your body, and be on the lookout for anything that is not normal.

Risk factors

Edward McCarron Colorectal Colon Cancer

Edward McCarron, MD, Oncologist, with patient

Research has shown that people with certain risk factors are more likely than others to develop colon cancer. Knowing your risks will help you and your doctor make the best health choices for you.

Risk factors may include:

  • Age — Most colon cancers are found in people over age 45. It is recommended at the age of 45 to schedule your first colonoscopy
  • Race or background — African-American or Jewish with Eastern European backgrounds are at a higher risk
  • Medical history — People with ulcerative colitis, Crohn’s disease, type 2 diabetes, or previous cancers have a higher risk of developing this disease
  • Family medical history — Close family members with colon cancer, as well as some conditions passed down through families, raise the risk
  • Lifestyle — The links between diet, weight and exercise, and risk are some of the strongest for any type of cancer. Some evidence suggests that colon cancer may be associated with a diet that is high in fat and calories and low in foods with fiber, such as whole grains, fruits, and vegetables

Are you 45 years of age or older?

If you answered yes, it may be time to get a colon cancer screening. Research has shown new cases of colorectal cancer are occurring at an increasing rate among younger adults. Experts have concluded colon cancer screening should begin at the age of 45 for adults of average risk. Take our free colon cancer risk assessment to learn if you are eligible for a colon cancer screening.

History questions

  1. Do you have a first-degree relative (parents, brothers, sisters, or children) with colorectal, endometrial, ovarian, urinary tract (including bladder, ureter, or kidney) gastric, small bowel, biliary, pancreatic, or brain cancer diagnosed before age 50?
  2. Have you had colorectal cancer or polyps diagnosed before age 50?
  3. Do you have at least three relatives with colorectal cancer?
hands collecting cancer ribbon

If you are age 45 or older, talk with your doctor about colon cancer screenings. If you have one or more risk factors for colon cancer, your doctor may want you to have screening exams earlier and more often.

Some people inherit colon cancer, but, in most people, no identifiable cause exists. Eating a healthy diet with plenty of fiber, not smoking, and getting exercise may help prevent colon cancer but, without a known cause, prevention is challenging. This is why screenings are important.

Are you eligible

Are You Eligible?

Doctor showing lower intestine 3d model to senior paitent


Beginning at age 45, men and women who are at average risk for developing colon cancer should be screened. Health care providers may suggest one or more of the tests listed below for colorectal cancer screening.

Colonoscopy: A lighted instrument called a colonoscope is used to inspect the rectum and entire colon. This procedure can find precancerous or cancerous growths throughout the colon, including the upper part of the colon, where they would be missed by sigmoidoscopy. It allows a physician to examine the entire large intestine (colon) for abnormalities, such as ulcers or benign polyps. If polyps are found, they will be removed during the procedure, reducing the risk of colon cancer. The procedure is painless, as you will receive sedation and are asleep during the procedure.

Double Contrast Barium Enema: X-rays of the colon and rectum are taken after the patient is given an enema with a barium solution and air is introduced into the colon. The barium and air help to outline the colon and rectum on the X-rays.

Fecal Occult Blood Test: This test checks for hidden blood in the stool. Studies have proven that this test, when performed every 1 to 2 years in people ages 45 to 80, reduces the number of deaths due to colon cancer.

Sigmoidoscopy: A lighted instrument called a sigmoidoscope is used to examine the rectum and lower colon. Sigmoidoscopy can find pre-cancerous or cancerous growths in the rectum and lower colon. Studies suggest that regular screening with sigmoidoscopy after age 45 can reduce the number of deaths from colorectal cancer.

Stool DNA Test: This test checks for cancer of all stages and in all locations in the colon.

Screening guidelines

Colon cancer screening tests can help prevent disease and save lives. U.S. Preventive Services Task Force recommends the following screenings for colon cancer beginning at age 45 through age 75:

  • A colonoscopy, which uses a flexible, lighted tube to look at the interior walls of the rectum and the entire colon, every 10 years
  • A flexible sigmoidoscopy, which uses a flexible, lighted tube to look at the interior walls of the rectum and part of the colon, every five years
  • A high-sensitivity fecal occult blood test (FOBT), which checks for hidden blood in the stool, every year

Many doctors today prefer a colonoscopy for detecting colorectal cancer because it lets them see the entire colon. Plus, if your doctor sees something unusual, polyps or tissue samples can be taken out right away.

No cost screening

If you are age 45 or older, live in Baltimore City or Anne Arundel County, and have a low income, you may be eligible for a no cost screening. Screenings are offered at four of our local hospitals, MedStar Franklin Square Medical Center, MedStar Good Samaritan Hospital, MedStar Harbor Hospital, and MedStar Union Memorial Hospital with transportation offered to and from appointments.

Our expertise can make a big difference in getting the right diagnosis and the right treatment, right away. Eligibility and coverage details for no cost screenings are provided below, or you can call 410-350-8216 or 410-350-3444 (Spanish) to see if you qualify.


  • A Baltimore City or Anne Arundel County resident
  • Age 45 or older
  • Under age 45 with symptoms or a family history of colon cancer
  • Living on a limited income


  • Health Insurance: We will pay for what Medicare, Medicaid, and Commercial Insurance doesn’t, including: deductibles, co-insurance, and out-of-pocket expenses
  • No Health Insurance: We will pay all the costs

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Watch how a colonoscopy could save your life

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