More Young Adults Are Getting Colon Cancer

For many years, colorectal cancer was thought of as a disease that mostly affected older adults. That is still partly true: age remains one of the most important risk factors.

But the story has changed. More adults in their 30s, 40s, and early 50s are being diagnosed with colorectal cancer than in previous generations. This trend has been concerning enough that national screening guidelines now recommend that average-risk adults begin colorectal cancer screening at age 45 instead of 50. As a colorectal surgeon, this is one of the most important messages I want younger adults to hear: colorectal cancer is not just an older person’s disease.

Why Is This Happening?

The honest answer is that we do not fully know. Researchers are actively studying why colorectal cancer is rising in younger adults. Several factors may be involved, including changes in diet, obesity, sedentary lifestyle, alcohol use, metabolic health, gut microbiome changes, environmental exposures, and other factors we may not yet fully understand. But this is important: you do not need to know exactly why a trend is happening in order to respond appropriately to it. If colorectal cancer is appearing more often in younger adults, then younger adults and their physicians need to take symptoms seriously, understand their family history, and follow screening recommendations.

Screening Now Starts at 45 for Average-Risk Adults

For average-risk adults, colorectal cancer screening should begin at age 45. That does not always mean colonoscopy is the only option. Depending on your personal risk, medical history, and preferences, screening may include colonoscopy or stool-based testing. But colonoscopy has one unique advantage: it can find and remove precancerous polyps during the same procedure. That matters because most colorectal cancers develop slowly over time from polyps. Removing those polyps can prevent cancer before it starts.

What If You Are Younger Than 45?

If you are younger than 45 and have no symptoms and no family history, routine screening may not be recommended yet. But symptoms should never be ignored simply because of age.

You should speak with a physician if you have:

• Rectal bleeding

• Blood in the stool

• A persistent change in bowel habits

• New constipation or diarrhea that does not resolve

• Unexplained weight loss

• Abdominal pain that persists

• Iron deficiency anemia

• A family history of colorectal cancer or advanced polyps

One of the most dangerous assumptions is, “I’m too young for colon cancer.” You may be young, healthy, and active — and still need an evaluation if symptoms are present.

Rectal Bleeding Is Not Always “Just Hemorrhoids”

Hemorrhoids are common. Anal fissures are common. Not every episode of bleeding means cancer. But bleeding should not be dismissed without thought, especially if it is new, persistent, associated with bowel habit changes, or occurring in someone with a family history. Many young patients are initially reassured that bleeding is probably hemorrhoids. Often, that is true. But sometimes it is not. A careful history, exam, and appropriate testing matter.

Family History Changes the Equation

If you have a first-degree relative — parent, sibling, or child — with colorectal cancer or advanced polyps, your screening may need to begin earlier than age 45.

The exact timing depends on the age of diagnosis and details of the family history. This is one of the reasons it is important to ask your relatives about colon cancer, colon polyps, and genetic cancer syndromes. Many people know that “cancer runs in the family” but do not know what type, at what age, or whether colon polyps were involved. Those details matter and are worth the conversation with your family.

Colon Cancer Is Often Preventable

The hopeful part of this discussion is that colorectal cancer is one of the cancers we can often prevent. Screening is not just about finding cancer early. With colonoscopy, screening can identify and remove precancerous polyps before they become cancer.

That is why screening matters even if you feel completely well. In fact, the best time to prevent colorectal cancer is before symptoms ever appear.

The Takeaway

More young adults are being diagnosed with colorectal cancer, and we do not yet have one simple explanation for why. But we do know what to do. Know your family history. Do not ignore symptoms. Begin average-risk screening at age 45. And if you are younger than 45 but something feels wrong, get evaluated. Being young does not make colorectal cancer impossible. Listening early can make all the difference.