NEW YORK, Aug 12: New research reveals a significant increase in colorectal cancer cases among younger adults in the U.S., with symptoms that often go unnoticed.

According to the American Cancer Society, the lifetime risk of developing colorectal cancer (CRC) is 1 in 24 for men and 1 in 26 for women. It ranks as the third leading cause of cancer-related deaths in men and the fourth in women — but when both genders are considered together, it's the second most common cause of cancer death.

While colorectal cancer may not present clear signs in its early stages, experts emphasize the importance of not ignoring certain symptoms.

Key symptoms you shouldn’t overlook

Changes in bowel habits can be a warning sign. The Colorectal Cancer Alliance notes that symptoms may resemble those of other conditions, such as hemorrhoids, infections, or irritable bowel syndrome (IBS). However, consistent changes like diarrhea, constipation, unusually narrow stools, or the sensation of incomplete bowel movements could point to CRC.

Fight Colorectal Cancer, a prominent advocacy organization, explains that shifts in bowel patterns can result from diet, medications, infections, or other health concerns—but persistent abnormalities should be checked by a doctor. Specifically, they advise seeking medical attention if:

Additionally, thin or pencil-shaped stools may suggest a possible blockage in the colon, such as a tumor, although other less serious causes are also possible.

Abdominal discomfort — including cramping, bloating, nausea, or a constant feeling of fullness—may indicate CRC. The Colorectal Cancer Alliance highlights these as warning signs. According to Fight CRC, intense or stabbing abdominal pain should prompt an emergency visit, but even mild, persistent pain should not be ignored.

Rectal bleeding is another red flag. Whether it's blood on the stool, in the toilet, or on toilet paper after wiping, Fight CRC warns that any rectal bleeding is abnormal and requires medical evaluation. Monitoring the frequency, location, and any pain associated with the bleeding can help with diagnosis.

Other possible warning signs

Unintended weight loss can sometimes point to cancer. The Colorectal Cancer Alliance urges anyone experiencing unexplained weight loss to consult a doctor.

As cancer cells grow, they consume the body’s energy, placing a greater demand on the immune system. According to Fight CRC, this can lead to fatigue, weakness, or even shortness of breath. These symptoms could also indicate anemia, especially if there is internal bleeding caused by a tumor.

Moreover, a tumor blocking part of the colon or intestine can interfere with nutrient absorption, further contributing to weight loss.