Colorectal cancer has long been associated with older adults. A growing body of research is challenging that assumption — and the latest data suggests one specific dimension of the problem is accelerating faster than most people realize.
A new study, scheduled to be presented at Digestive Disease Week 2026 in Chicago, has found that rectal cancer mortality among Americans aged 20 to 44 is rising at a rate two to three times faster than that of colon cancer in the same age group. The researchers analyzed Centers for Disease Control and Prevention (CDC) death records spanning 1999 to 2023, then used a machine learning model to project where the trend is heading.
Where it is heading, by their calculations, is worse.
“Colorectal cancer is no longer considered predominantly a disease of older adults,” said Mythili Menon Pathiyil, the study’s lead author and a gastroenterology fellow at SUNY Upstate Medical University. “Rectal cancer, especially, is becoming a growing problem in younger individuals.”
Who Is Being Hit Hardest
The mortality gap between rectal and colon cancer is widening across every demographic the researchers examined — but some groups are facing steeper increases than others.
Hispanic adults and residents of Western states experienced the sharpest rises in rectal cancer deaths, according to the study. The finding points toward potential geographic and population-specific factors — including possible differences in healthcare access, screening rates, and environmental or dietary exposures — that researchers say warrant further investigation.
For older millennials specifically — those between the ages of 35 and 44 — the trajectory is particularly concerning. The study projects that rectal cancer mortality in this cohort will continue to climb through 2035 without a meaningful shift in how the disease is detected and treated.
The Diagnostic Delay That Is Costing Lives
At the heart of the worsening outcomes for young adults is a problem that plays out at the most fundamental level of medical care: the time between first symptoms and first treatment.
For older patients, that window tends to be short — roughly one month from the onset of symptoms to the beginning of care. For young adults, the average delay is seven months.
That six-month gap is not a minor inconvenience. In cancer, time from initial symptoms to treatment is directly linked to how advanced the disease becomes before it is caught — and how survivable it remains.
Dr. Rachel Gordon, a New York-based colorectal and general surgeon at Episcopal Health Services who was not involved in the study, described the pattern she is observing in her own practice.
“Young people are being diagnosed with rectal cancers at increasingly younger ages — and often at more advanced, aggressive stages of disease,” Gordon told Fox News Digital.
Why Young Patients Wait So Long
The delay is not purely a result of patients ignoring symptoms. A significant part of the problem, researchers say, lies with the medical system itself.
Pathiyil flagged a specific pattern that contributes to delayed diagnoses: primary care providers frequently dismiss concerning symptoms in young patients — particularly rectal bleeding and changes in bowel habits — as signs of benign conditions like hemorrhoids, rather than prompting further investigation.
For a young person with no family history of cancer and no prior screening, the reassurance from a physician that “it’s probably nothing serious” can be enough to delay follow-up for months — or until symptoms become impossible to ignore.
“We’re seeing a combination of lifestyle and environmental exposures, including diet and changes in the gut microbiome, potentially playing a role,” Gordon added, reflecting on the broader question of why younger adults are increasingly developing rectal cancer in the first place.
Warning Signs That Should Not Be Ignored
Both the study’s authors and the physicians commenting on its findings were emphatic about one practical takeaway: younger adults experiencing specific symptoms need to seek evaluation — and not accept a dismissal without further investigation.
Gordon outlined the red-flag symptoms that warrant medical attention:
Rectal bleeding — whether bright red or dark in color. Persistent changes in bowel habits, including chronic diarrhea or constipation. Narrow stools. A persistent feeling of incomplete bowel emptying. Abdominal pain. Unexplained weight loss. And unexplained fatigue.
“If something doesn’t feel right, or if you experience symptoms such as these, it’s important to see your doctor promptly,” Gordon said.
The emphasis on promptness is not incidental. Seven months of delay, in a disease that advances as aggressively as rectal cancer can in younger patients, is a window that cannot be recovered.
What Needs to Change
The study’s findings carry direct implications for current colorectal cancer screening guidelines, which are primarily designed around older adults.
Pathiyil was direct about where things need to go from here.
“Our study shows that rectal cancer is driving much of the increase in colorectal cancers. It’s likely to worsen over time if we don’t change what we are doing right now.”
What that change looks like — whether it means lower the screening age, expanding guidelines for high-risk younger populations, or training primary care physicians to approach red-flag symptoms in young adults with greater urgency — is a question the medical community will need to answer with increasing speed as the data continues to accumulate.
The data from this study does not allow for comfortable reassurance. Rectal cancer deaths among young Americans are rising faster than those for colon cancer, the gap is widening across every demographic, and the trajectory points toward continued worsening through at least 2035 without intervention. The seven-month average delay between first symptoms and treatment in young adults is not an abstract statistic — it represents the real cost of a medical system and a cultural assumption that has not yet caught up with a disease that is no longer waiting for people to turn 50. The researchers are calling for change. The question is whether the response will come fast enough to matter.
