Colorectal Cancer: Learn the Symptoms, Who’s at Risk, and When to Get a Colonoscopy

The rate of colorectal cancer diagnoses has decreased overall in the U.S., likely due to regular screenings and lifestyle changes, according to the American Cancer Society (ACS). However, for those under 50, the risk is rising: Today, colorectal cancer — which includes cancers of the colon and rectum — is the leading cause of cancer death in people younger than 50.   

“There are some possible explanations for the sudden increase, but we don’t know for sure,” says Dr. Sheila Rustgi, a gastroenterologist at NewYork-Presbyterian/Columbia University Irving Medical Center. “One thing we do know — without question — is that, with appropriate and timely screening methods, colon cancer is highly preventable.”

To learn the facts about colorectal cancer, Health Matters spoke with Dr. Rustgi, who explains what to know about colon cancer symptoms, the importance of colonoscopies, and the steps you can take to lower your risk.

Why is colon cancer rising in young people?

Certain factors have been associated with the rise in early onset colorectal cancer. Some of these factors are modifiable, meaning you can change your behavior to alter the risk. These risk factors include:

• Obesity
• A diet high in processed foods and sugar-sweetened beverages without a lot of fiber
• Sedentary lifestyle
• Cigarette smoking
• Heavy alcohol consumption

A recent study sheds light on the impact of ultraprocessed foods, suggesting increased consumption of processed, non-whole foods can increase the risk of developing early-onset colorectal cancer.

“I encourage all patients who are concerned about their cancer risk to quit smoking, aim for 150 minutes of exercise a week, and incorporate fruits and vegetables for increased fiber intake,” says Dr. Rustgi.

Who is at risk for colorectal cancer?

Colorectal cancer is the third most commonly diagnosed cancer in both men and women in the United States. Having certain genetic predispositions does increase a person’s risk, but colorectal cancer can still occur in people with no family history of the disease. And while colorectal cancer impacts all populations, African Americans are about 20% more likely to get colorectal cancer and about 40% more likely to die from it.

When should I get screened for colorectal cancer?

In 2021, the U.S. Preventive Services Task Force updated its guidelines to recommend everyone get screened for colorectal cancer starting at age 45, no matter their family history. This reflects the ACS’s guidelines, which were updated in 2018.

“Colorectal cancer can affect everyone, and screening saves lives,” says Dr. Rustgi.

If you have a family history, get screened ten years earlier than the age at which your relative was diagnosed (or at 40, whichever comes first). If you have any symptoms like a persistent change in your bowel habits, rectal bleeding, persistent abdominal discomfort, or a feeling that your bowel doesn’t completely empty, discuss them with your doctor regardless of age and consider getting a colonoscopy.

Is a colonoscopy painful?

A colonoscopy is an exam that detects abnormalities in the large intestine (colon) and rectum. It is conducted while a patient is under anesthesia, so the patient feels no pain during the procedure.  

The preparation for a colonoscopy is typically painless, as well. “The day before your colonoscopy, you can work normally, but you’ll be on a limited diet, which might mean clear liquids like chicken broth or a small low-fiber breakfast like eggs and white toast,” says Dr. Rustgi. “You’ll also be prescribed a laxative solution that you drink in stages. This is to flush out the colon. It doesn’t taste good and can be a little nauseating, but there shouldn’t be any pain.”

The procedure itself is only 30-45 minutes, during which patients are sedated with anesthesia while gastroenterologists search for and remove any polyps. Cutting out these small clumps of cells that form on the lining of the colon can prevent the polyps from growing into tumors.

Colonoscopies continue to be the gold standard in preventing and detecting colon cancer. They are safe, effective, and can save your life. “A colonoscopy is a relatively small inconvenience compared to potentially missing an early onset colorectal cancer,” says Dr. Rustgi. “It’s one day of your life, hopefully not more frequent than once every 10 years to prevent colon cancer.”

What else can you do to prevent colorectal cancer?

A colonoscopy is not the only method for detection. Noninvasive stool-based screening tests are a convenient way to detect colorectal cancer early, when it is easiest to treat and is potentially curable. They don’t require any special diets or procedures and can be done at home and submitted to a lab where the sample is tested for precancerous and cancerous cells.

These tests are a good option for patients who are at average risk (don’t have a family history of colorectal cancer and who have not had polyps in the past) but have other barriers to a colonoscopy, such as needing to take time off work, find child or elder care, or need an escort afterwards.

It is important to note that noninvasive screening is not recommended for people who have had polyps in the past or a family history of colorectal cancer. It’s also important to note that stool-based screenings can’t match the benefits of a colonoscopy since precancerous colon polyps are not removed. “If a stool-based screening test is positive, you will need to have a colonoscopy to find out why,” says Dr. Rustgi.

Remember that the benefit of doing colon cancer screenings is not only to try and prevent colon cancer, but also to find it at an early stage. The earlier the stage, the more treatment options there are.

“The most important thing is to get screened when you need to,” says Dr. Rustgi. “You can discuss with a doctor what the best option is for you in your personal situation — whether that’s a colonoscopy or a stool-based test.”

Sheila Rustgi, M.D., is a gastroenterologist at NewYork-Presbyterian/Columbia University Irving Medical Center and an assistant professor of medicine at Columbia University Vagelos College of Physicians and Surgeons. Dr. Rustgi has a special interest in the prevention and early detection of gastrointestinal cancers. She has published on the care of patients with pancreatic cancer, inflammatory bowel disease, and the impact of health insurance on patient care. Dr. Rustgi’s clinical interests include colon cancer screening, Crohn’s disease, ulcerative colitis, and general GI diagnoses such as IBS, as well as the care of patients at high risk for gastrointestinal cancer due to an inherited cancer syndrome.