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You May Have Colon Cancer and Not Know It. Here are the Signs.

Get screened when it’s time.
FACT CHECKED BY Emilia Paluszek

Colon cancer is quite common, being found in one in roughly 25 people during their lifetime. It is the second most common cause of cancer deaths currently in the United States. Today we know that colon cancer is being diagnosed in an even younger population, and ~10% of new cases occur in patients under the age of 50. Recently, screening guidelines have changed, suggesting that colorectal cancer screening should begin at age 45 in patients without a family history. Read on to discover the symptoms.


Can you have colon cancer and not know it?

Young woman suffering pain at bedroom

It is not uncommon to have colon cancer and not know about it, as early cancers often do not have any symptoms. This is often because the cancers are so small that they don't cause any noticeable symptoms such as pain, bleeding, or a bowel blockage. Also, sometimes in younger patients, cancer is not often explored as a possible cause of symptoms early in the workup. 


What lifestyle choices can lower your risk of getting colorectal cancer?

eat fiber foods


We know that diets that include fruits, vegetables, and whole grains have been linked with a decreased risk of developing colon and rectal cancer. We also know that diets high in red meat (beef, pork, lamb) and/or processed meat (hotdogs, lunch meat) are linked with an increased risk of colorectal cancer. Additionally, smoking is also associated with an increased risk of developing colorectal cancer. 


What are symptoms of colon cancer?

man prostate cancer, premature, ejaculation, fertility, bladder problem

Many times there are no warning signs, unfortunately. For patients with a cancer in the left side of the colon, bleeding with bowel movements may be mistakenly attributed to hemorrhoids. People may also dismiss new difficulties passing their bowel movements or new bloating as constipation or irritable bowel syndrome, when it could represent a tumor, which is causing a blockage. Unexplained or unanticipated weight loss can also be a warning sign of cancer in general.


What should you know if you're newly diagnosed with colon cancer?

prostate cancer

The first question a patient should ask their physician after a diagnosis is the stage of their disease. This usually entails a discussion of the involvement of the cancer in the colon, the surrounding lymph nodes, and any other organs in the chest, or abdomen. Depending what is found on the initial CT scans, a patient's physician can make the appropriate referrals to a colorectal surgeon and possibly a GI medical oncologist. 

If patients have a strong family history of colon or rectal cancer, they should make sure that appropriate genetic testing is performed. They should also ask if testing has been performed on their particular tumor or biopsy specimen, for the most common genetic markers of colon cancer. The presence or absence of these markers can often be helpful in determining what chemotherapeutic agents may be successful. Finally, as any cancer, diagnosis can cause enormous amount of stress, and/or financial burden, they should ask their physician or oncologist about support programs, which may exist at their cancer center to help them process their new diagnosis.


Are colonoscopies important?

Gastrologist. Doctor's office. Doctor gastroenterologist with probe to perform gastroscopy and colonoscopy

Colorectal cancer screening is very important – as Colon and rectal cancers can be prevented by the removal of polyps in the colon before they can develop into a cancer. Early cancers can also be removed endoscopically before they become invasive.  

It is important that patients start their screening at the appropriate age – 45 for those without a family history of colon and rectal cancer, and potentially earlier, for those with a strong family history (discussion of the age of first screening, and screening modality can be discussed with your primary care, physician or gastroenterologist). 

Based upon the findings, in the first colonoscopy, your gastroenterologist can let you know how often you will need to follow up, and what follow up screening methods are available.

Anne Mongiu, MD, PhD
Anne Mongiu, MD, PhD, is a Yale Medicine Colorectal Surgeon Read more about Anne
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