4 Early Symptoms of Colon Cancer Young Adults Should Know

Colorectal cancer (CRC) is the third most common cancer diagnosed in the United States. Recent studies have found that the cancer is becoming increasingly common among young adults.

Colorectal cancer symptoms can go unnoticed in the early stages of the disease. Now, a team of researchers at the Washington University School of Medicine in St. Louis has identified four “red flag” symptoms that could be signs of early-onset colorectal cancer.

Here’s what experts say you should know about the signs of early colorectal cancer and what to do if you have them.

What Are the Early Signs of Colorectal Cancer in Young Adults?

The study, which was published in the Journal of the National Cancer Institute, found that there are four symptoms that can be early warning signs for colorectal cancer:

• Abdominal pain
• Rectal bleeding
• Ongoing diarrhea
• Iron deficiency anemia

According to the study, these symptoms appeared at least two years before a colorectal cancer diagnosis.

“Our findings are important and timely because of the rising incidence of colorectal cancer in young adults,” Cassandra Fritz, MD, MPHS, a first author of the study and an assistant professor of medicine in the Division of Gastroenterology at Washington University School of Medicine, told Verywell. “Awareness of these symptoms could improve earlier detection of early-onset colorectal cancer.” 

The More Symptoms You Have, the Higher Your Risk

The number of colorectal cancer cases diagnosed in people younger than the age of 55 almost doubled from 11% to 20% between 1995 and 2019, according to data from the American Cancer Society.

Fritz and colleagues analyzed health insurance data for more than 5,000 patients with early-onset colorectal cancer (diagnosed under the age of 50). The researchers’ goal was to find symptoms that could be early signs of colorectal cancer, especially in young adults.

The study showed that in the three months to two years before getting diagnosed, the patients who had symptoms like abdominal pain, rectal bleeding, ongoing diarrhea, and iron deficiency anemia had a higher risk of having early-onset CRC.

According to Fritz, nearly half of the patients reported having at least one of those symptoms in the three months before they were diagnosed.

“We hope patients and providers are aware of the 4 symptoms we found to be associated with early-onset CRC,” said Fritz. “Some patients in our study had symptoms for about 2 years before getting a diagnosis. Early detection is critical!”

The researchers also found that the more symptoms a person had, the higher their risk of getting diagnosed with colorectal cancer was.

For example, having one symptom nearly doubled a patient’s risk of the disease, having two symptoms increased the risk by more than 3.5 times, and having three or more raised the risk by more than 6.5 times.

If You Have Symptoms, Screening Matters—No Matter How Old You Are

In a news release about the study, senior investigator Yin Cao, ScD, MPH, an associate professor of surgery and a research member of the Siteman Cancer Center at Barnes-Jewish Hospital and Washington University School of Medicine, said that if you’re having symptoms like rectal bleeding and iron deficiency anemia, you should talk to your provider about getting checked for colorectal cancer.

Even if you think you’re too young for screenings, Cao said to remember that “colorectal cancer is not simply a disease affecting older people.”

“We want younger adults to be aware of and act on these potentially very telling signs and symptoms,” said Cao. “Particularly because people under 50 are considered to be at low risk, and they don’t receive routine colorectal cancer screening.”

The Signs Might Not Mean Cancer

Anton Bilchik, MD, PhD, surgical oncologist and division chair of general surgery at Providence Saint John’s Health Center and chief of medicine and director of the Gastrointestinal and Hepatobiliary Program at Saint John’s Cancer Institute told Verywell that most of the symptoms associated with colorectal cancer can also be signs of many common conditions.

For example, food poisoning or viral gastroenteritis can cause abdominal pain and diarrhea, and inflammatory bowel conditions like ulcerative colitis and Crohn’s disease can cause bloody stool and anemia. 

“These symptoms are not specific for colon cancer,” said Bilchik. “There is no specific symptom that’s related to colon cancer because there are so many other conditions that can have similar symptoms.”

However, Bilchik said that all patients—no matter their age—should contact their healthcare provider right away if they are having symptoms to find out what’s causing them.

“If you have more than one of those symptoms, you need to strongly consider a diagnosis other than what is most common among young people, which could be gastroenteritis, colitis, or hemorrhoids,” said Bilchik.

Should You Get Screened If You Don’t Have Symptoms?

If you are not having symptoms, Bilchik still recommends taking proactive measures like getting screened for colorectal cancer. The earlier cancer is diagnosed, the earlier treatment can start—which may lead to better outcomes.

“Younger people need to be aware that colon cancer is no longer an older person’s disease, and that it is going up exponentially among people under age 50,” said Bilchik. “There’s no excuse not to get screened because we now have stool-based tests which can be done from the home.” 

Tracey Childs, MD, board-certified in general and colorectal surgery and vice chair of surgery at Providence Saint John’s Health Center told Verywell that screening is especially important for certain people who may have a higher risk for colorectal cancer:

• People with genetic mutations for diseases like Lynch syndrome
• People with a personal or family history of inflammatory bowel disease
• People with a history of abdominal or pelvic radiation therapy
• People with a history of cystic fibrosis or diabetes
• People who smoke cigarettes and/or consume alcohol
• People who eat a lot of red and/or processed meat
• People who have obesity

Can You Lower Your Risk for Colorectal Cancer?

Childs said there are some things you can do to decrease your risk of developing colorectal cancer:

• Talk to your provider about screenings
• Get regular physical activity
• Eat a nutritious diet with plenty of fruits and vegetables
• Get your cholesterol levels tested and keep them in check
• Achieve and maintain a weight that supports your health
• Limit alcohol
• Avoid tobacco and quit if you use