What is rectal cancer?
The rectum is the last few inches of your large intestine (colon). It connects the colon to the anus. Rectal cancer happens when cells in the rectum grow when they should not and form a lump, called a tumor.
Rectal cancer is related to colon cancer. Together, they are called colorectal cancer. They affect different parts of the digestive system and can cause different symptoms.
Why are people talking about rectal cancer more?
You may have seen news stories about rectal cancer in younger adults. Here is what health care providers and researchers know:
- Colorectal cancer is becoming more common in adults under age 50.
- Rectal cancer is the type that is increasing the fastest in this age group.
- Even with this rise, rectal cancer is an uncommon diagnosis in young adults.
Health care providers and researchers are paying close attention because finding cancer early makes treatment easier and more successful.
The goal is awareness, not fear.
Putting the risk of rectal cancer in perspective
It is important to understand the numbers in a clear way:
- For adults under 50, rectal cancer is still rare.
- In any given year, far fewer than 1 out of 7,000 younger adults are diagnosed.
- Over a lifetime, about 4–5 out of 100 people will be diagnosed with colorectal cancer, and most of that risk happens after age 50.
Most young adults will never develop rectal cancer.
Many younger people with rectal cancer wait months before seeing a doctor. This can delay diagnosis. On average, there can be a 7-month gap between when symptoms start and when a diagnosis is made.
Colon and rectal cancers are very treatable when found early, so recognizing symptoms matters.
Talk to your health care provider if any of the symptoms below last more than a few days:
- Blood in your stool or on toilet paper (bright red blood is common with rectal cancer)
- Feeling a strong need to have a bowel movement, even after you just went
- Changes in bowel habits that do not go away:
- New diarrhea or constipation
- Stools that look thinner or different from usual
- Ongoing belly pain
- Losing weight without trying
- Feeling very tired for no clear reason
- Low iron levels (iron-deficiency anemia)
These symptoms are usually caused by something else, such as hemorrhoids, infections, or diet changes. But it is still important to get checked to make sure it is not cancer.
A helpful question to ask your health care provider is: Could this be colorectal cancer?
What may increase your risk for rectal cancer?
Scientists are still studying why rectal cancer is rising in younger adults. Most young people diagnosed do not have a known cause.
Things that may raise risk include:
- Eating a lot of processed meats (hot dogs, sausage, deli meats).
- Eating a lot of red meat and refined grains (white bread, white rice).
- Drinking sugary drinks, especially 2 or more per day.
- Being overweight or gaining weight early in life.
- Not getting much physical activity.
- Smoking.
- Drinking alcohol.
- Having inflammatory bowel disease (IBD, Crohn’s disease or ulcerative colitis).
- Having a family history of colorectal cancer (a parent, sibling, or child).
Many younger patients have none of these risk factors, which is why knowing symptoms matters.
When should you get screened?
Screening means checking for cancer before you have any symptoms.
Common screening options include:
- Colonoscopy, where a doctor looks inside the colon and rectum with a small camera.
- Stool tests, which check for hidden blood or cancer-related changes.
General screening guidance:
- Age 45 and older: Everyone at average risk should start screening.
- Before age 45: You may need earlier screening if you have a family history or other risk factors.
Your health care provider can help you choose the right test and timing.
What can you do to lower your risk of rectal cancer?
There is no sure way to prevent rectal cancer, but these habits can help lower risk:
- Eat more fruits, vegetables, and whole grains
- Cut back on processed meats, red meat, and sugary drinks
- Stay at a healthy weight
- Be active most days (aim for about 30 minutes a day)
- Do not smoke
- Limit alcohol
- Know your family health history
- Do not ignore symptoms. If you have warning signs like bleeding or bowel changes, talk to your doctor right away
The bottom line
Rectal cancer is becoming more common in younger adults, but the overall risk is still low. Knowing the warning signs, living a healthy lifestyle, and speaking up about symptoms can make a real difference.
Rectal cancer is very treatable when found early.
Talk to your health care provider if you have questions about your personal risk or when to start screening.
Reviewed by
Jessica D. Korman, MD
Capital Digestive Care, Washington, DC
AGA Patient Education Advisor
Folasade (Fola) Popoola May MD, PhD, MPhil
Assistant professor of medicine, University of California, Los Angeles (UCLA), Health
May 2026