Colorectal cancer is among the top three most common cancers in men and women in the United States. According to the American Cancer Society, lifetime risk of developing colorectal cancer is about 1 in 23 for men and 1 in 26 for women—although a person’s likelihood depends on their specific risk factors. 

Until recently, colorectal cancer was found primarily in older adults, but since the early 2000s, studies have shown an increase in colorectal cancer in adults younger than 50. (In 2021, the U.S. Preventive Services Task Force lowered its recommended age at which average-risk adults should begin getting screened for colorectal cancer from 50 to 45.) 

Signs and Symptoms of Colorectal Cancer

Unfortunately, many people with colorectal cancer may not “feel anything” or may not see early signs of it.

“The very first signs of colorectal cancer are often subtle,” says Michael P. Del Rosario, M.D., a colorectal surgeon at Southern Ocean Medical Center. 

He says there’s a misconception that if you don’t feel anything amiss in your abdomen, there’s no reason to consider the possibility of colorectal cancer. Unfortunately, being asymptomatic is quite common, which makes proactive screening so important. 

“Most newly diagnosed colon cancers are picked up in completely asymptomatic people through screening,” Dr. Del Rosario says. “You don’t want to wait for symptoms.”

That said, if you experience these symptoms over a prolonged period of time, talk to your doctor:

• Fatigue: A slowly growing tumor can cause a person to be anemic, Dr. Del Rosario says. The lower level of healthy red blood cells causes tiredness.
• A change in your bowel movements: Constipation and diarrhea are common, but if either persists for months, you should talk to your doctor about it, Dr. Del Rosario says. A change in the shape of your stool may also be problematic. A growing tumor may narrow the passageway your stool moves through, causing it to become thin.
• Rectal bleeding or blood in the stool: Most rectal bleeding is not cancer, Dr. Del Rosario says. Usually, it’s hemorrhoids. If you regularly see blood in your stool or in the toilet bowl after a bowel movement over several months, talk to your doctor.
• Unexplained abdominal pain: The pain associated with a growing tumor may come and go. It can feel like gas, burning or a nagging discomfort. Even if the pain doesn’t double you over, if it persists for several weeks, you should talk to your doctor about it, Dr. Del Rosario says.  
• Unexplained weight loss: As a tumor grows, it absorbs more of your proteins and other nutrients, leading to weight loss.

Next Steps & Resources:

• Meet our source: Michael P. Del Rosario, M.D.
• To make an appointment with a gastroenterologist near you, call 800-822-8905 or visit our website.
• Take this colon cancer risk assessment to find out if you're at risk for colon cancer, and when you should be tested.
• Make an appointment for a colonoscopy.

The material provided through HealthU is intended to be used as general information only and should not replace the advice of your physician. Always consult your physician for individual care.