Colorectal cancer has become the Leading cause of cancer-related death among people under 50 years of age.. Although routine screening typically begins at age 45 for average-risk adults, warning signs may appear earlier and should be discussed with a healthcare provider at any age.
To help people recognize possible symptoms and talk to their doctors sooner, the American College of Surgeons (ACS) has introduced free public education resources and checklist Designed for use before primary care appointments.
Colorectal cancer is increasing in younger adults
“Many times, when younger patients seek care for bowel symptoms, those symptoms are too often attributed to hemorrhoids or constipation and are treated conservatively,” said Marylise Boutros, MD, FACS, FRCSC, FASCRS, member of the ACS Patient Education Committee, colorectal surgeon and vice president of Digestive Diseases Research at Cleveland Clinic Florida, who helped develop the new ACS educational materials. “As more young people are diagnosed with colorectal cancer, awareness of the subtle signs and symptoms of the disease can save lives. The ACS educational materials and checklist were created to help patients clearly raise their concerns and keep conversations about colorectal cancer focused.”
The disease is still diagnosed more frequently in older adults, and approximately 1 in 25 men and women will develop colorectal cancer during their lifetime. Even so, diagnoses among younger people have continued to increase.
According to the American Cancer Society, about 1 in 5 cases of colorectal cancer now occur in people under 54 years of age. Three decades ago, that figure was 11% (about 1 in 10).
Colorectal cancer symptoms that need attention
Early signs of colorectal cancer may be mild, vague, or easy to confuse with common digestive problems. However, new, persistent, or unusual symptoms should not be dismissed without medical evaluation.
The ACS checklist draws attention to several potential warning signs.
Persistent changes in bowel habits
Constipation, diarrhea, unusually narrow stools, or a lasting change in normal bowel habits may indicate an underlying problem. Some people may also feel as if the bowel has not emptied completely.
Rectal pressure or discomfort may also occur. These symptoms can develop when a tumor causes inflammation or partially blocks the intestine.
“In younger patients, these symptoms can sometimes be due to non-cancerous conditions,” said Paula Denoya, MD, FACS, FASCRS, state chair of the Eastern Long Island-New York Chapter Commission on Cancer (CoC) and a colorectal surgeon at Stony Brook University Hospital in New York. “However, any bowel changes that are new or different for you deserve medical attention. An annual wellness visit is a good time to raise these concerns.”
Recurrent blood in stool
Blood in the stool is a major warning sign of colorectal cancer, especially when it appears more than once.
Investigation presented at the 2025 ACS Clinical Congress examined patients under age 50 who received a colonoscopy because they were experiencing symptoms. Rectal bleeding was the strongest predictor of a colorectal cancer diagnosis, increasing the odds 8.5 times.
“Bleeding is the most common symptom of colorectal cancer, but it can also be caused by other diseases,” said James T. McCormick, DO, FACS, FASCRS, CoC state president of the Southwestern Pennsylvania chapter, professor of surgery at Drexel School of Medicine, and chair of the Colorectal Cancer Program at Allegheny Health Network in Pittsburgh, Pennsylvania. “People may notice bright red blood on the toilet paper or in the bowl, or it may cause a red or dark color when mixed with stool. Any recurrent blood should be evaluated and a colonoscopy may be indicated to determine the underlying cause.”
Changes in the color or appearance of stool
Changes in the appearance of stool may provide additional clues. Bright red stools, dark or tarry stools, or mucus in the stool may be associated with bleeding somewhere in the gastrointestinal tract, colon, or rectum.
These changes do not always mean cancer is present, but they should be evaluated to see if they continue or recur.
Unexplained changes in general health
Colorectal cancer and other gastrointestinal conditions can sometimes cause symptoms that affect the entire body.
Unexplained weight loss, persistent tiredness, weakness, reduced appetite, nausea, or vomiting may indicate an underlying medical problem and warrant a conversation with a healthcare provider.
Screening for family history and colorectal cancer
He US 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 those with a family history of colorectal cancer and people with inflammatory bowel conditions such as Crohn’s disease or ulcerative colitis.
Several colorectal cancer screening methods are available. Colonoscopy is still considered the gold standard because it allows doctors to identify cancer and remove precancerous polyps during the same procedure.
“Colorectal cancer is highly treatable when detected early, and surgical advances continue to make treatment less invasive,” said Dr. Boutros. “I encourage patients to be proactive and use the checklist to start a conversation with their primary care provider about any concerning bowel changes.”