Colorectal cancer is the leading cause of cancer-related deaths in people under 50 years of age. Regular screening usually begins at age 45 for average-risk adults, but red flags may appear earlier, so you should talk to your health care provider at any age.
To help people be aware of possible symptoms and see a doctor sooner, the American College of Surgeons (ACS) has introduced a free public education resource and checklist designed to be used before a primary care appointment.
Colorectal cancer is increasing among young people
“When young patients seek treatment for bowel symptoms, those symptoms are often attributed to hemorrhoids or constipation and are treated conservatively,” says Maryse Boutros, MD, FACS, FRCSC, FASCRS, a member of the ACS Patient Education Committee and a colorectal surgeon and vice chair for gastroenterology research at the Cleveland Clinic in Florida, who helped develop the new ACS materials. “As more young people are diagnosed with colorectal cancer, being aware of the subtle signs and symptoms of the disease can save lives. ACS educational materials and checklists were created to help patients clearly express their concerns and focus the conversation about colorectal cancer.”
The disease is still often diagnosed in older adults, and approximately 1 in 25 men and women will develop colorectal cancer during their lifetime. Still, diagnoses continue to increase among young people.
According to the American Cancer Society, approximately 1 in 5 colorectal cancer cases currently occur in people under the age of 54. Thirty years ago, that number was 11% (about 1 in 10 people).
Symptoms of colorectal cancer to be aware of
The first signs of colorectal cancer may be mild and vague, and may be easily mistaken for common digestive disorders. However, new, persistent, or unusual symptoms should not be ignored without medical evaluation.
The ACS Checklist alerts you to several possible warning signs.
Persistent changes in bowel habits
Constipation, diarrhea, unusually thin stools, or persistent changes in normal bowel habits may indicate an underlying problem. Some people feel like their bowels are not completely empty.
Rectal pressure and discomfort may also occur. These symptoms can occur when a tumor causes inflammation or partially blocks the intestine.
“In younger patients, these symptoms may be due to non-cancerous conditions,” said Paula DeNoya, MD, FACS, FASCRS, state chair of the Commission on Cancer (CoC) of the Eastern Long Island New York Chapter and a colorectal surgeon at Stony Brook University Hospital in New York. “But any changes in your gut that are new or unusual to you are worth seeing your doctor. Your annual checkup is a good time to raise these concerns.”
Blood in the stool recurs
Blood in the stool is an important warning sign of colorectal cancer, especially if it occurs multiple times.
The study, presented at ACS Clinical Meeting 2025, looked at patients younger than 50 who underwent a colonoscopy because they had symptoms. Rectal bleeding was the strongest predictor of colorectal cancer diagnosis, increasing the odds by 8.5 times.
“Bleeding is the most common symptom of colorectal cancer, but it can also be caused by other diseases,” said Dr. James T. McCormick, CoC state chair of the Southwest Pennsylvania Chapter, professor of surgery at Drexel School of Medicine, and chair of the colorectal cancer program at Allegheny Health Network in Pittsburgh, Pennsylvania. “You may notice bright red blood on the toilet paper or in the toilet bowl. It may also be red or dark in color when mixed with the stool. Any amount of blood that recurs should be tested and may require a colonoscopy to determine the underlying cause.”
Change in stool color or appearance
Changes in the appearance of the stool may provide further clues. Bright red stools, dark or tarry stools, or mucus in the stool may be related to bleeding somewhere in the gastrointestinal tract, colon, or rectum.
These changes do not necessarily mean cancer is present, but should be evaluated if they persist or recur.
Unexplained changes in overall health
Colorectal cancer and other digestive disorders can cause symptoms that affect the entire body.
Unexplained weight loss, persistent fatigue, weakness, loss of appetite, nausea, or vomiting may indicate an underlying medical problem and should be discussed with your health care provider.
Family history and colorectal cancer screening
The U.S. Preventive Services Task Force recommends that adults at average risk begin screening for colorectal cancer at age 45.
Some people may need to start earlier. This includes people with a family history of colorectal cancer or inflammatory bowel diseases such as Crohn’s disease or ulcerative colitis.
There are several ways to screen for colorectal cancer. Colonoscopy is still considered the gold standard because it allows doctors to identify cancer and remove precancerous polyps during the same surgery.
“Colorectal cancer is highly treatable if detected early, and surgical advances continue to make treatments less invasive,” Dr. Boutros said. “I encourage patients to be proactive about any changes with their bowel movements and use the checklist to start a conversation with their doctor.”
