Colorectal Cancer Symptoms, Screenings and Treatment: 5 Things To Know in 2025

Colorectal cancer is a cancer of the lower gastrointestinal tract. Excluding skin cancers, it is the third most common cancer diagnosed in both men and women in the United States.

It is often thought of an older man’s disease, but women and men of all ages can develop colorectal cancer. In the past few years, there has been a rise in colorectal cancer diagnoses among people younger than 50. 

According to the American Cancer Society, colorectal cancer rates have been increasing by 1% to 2% a year since the mid-1990s in people younger than 55. It is now the No. 1 cause of cancer death in men under 50 and the No. 2 cause of cancer death in women under 50.

Colorectal cancer is curable if caught early, and many cases can be cured with surgery alone. Symptoms can be tricky to catch, as they’re often associated with other health conditions. Sometimes there are no symptoms until colorectal cancer has advanced, which is why screening is so important.

Colorectal cancer screenings

Adults at average risk for colorectal cancer should get a screening colonoscopy every 10 years beginning at age 45.

People with a family history of colorectal cancer should start getting screened 10 years before the youngest case in their immediate family. For example, if your father got diagnosed at 47, you should start getting screened at 37.

Screening in seemingly “healthy” or asymptomatic patients is important because colon cancer, especially in the right side of the colon, can grow quite large with absolutely no symptoms. Larger and more advanced the cancers generally see worse outcomes.

What are signs and symptoms of colorectal cancer?

According to the American Cancer Society, more than 107,320 people will be diagnosed with colon cancer in 2025. The group estimates more than 46,950 people will be diagnosed with rectal cancer.

Symptoms to be aware of include:

• Changes in bowel habits. Diarrhea and/or constipation, whether occasional or constant, may be a sign of colorectal cancer.
• Abdominal discomfort. Be on the lookout for symptoms including as persistent cramps, gas, pain, feeling unusually full or bloated or feeling like your bowels aren’t totally empty after you go to the bathroom.
• Rectal bleeding. Call your doctor if there is blood in your stool. This can range from bright red, brick red to black and tarry.
• Weakness or fatigue: Anemia or a low red blood cell count can also be indicators.
• Unexplained weight loss. This unintentional weight loss may be accompanied by nausea or vomiting.
• Unusual stools. Look for any differences in your stool from color or shape. Be especially aware of thin pencil-like stools, which could indicate that something may be blocking your bowel movements.

If you’re experiencing symptoms, talk to your doctor about getting screened for colorectal cancer. Based on your family history, symptoms and risk factors, your doctor may want to start screening you early or screen more frequently.

What is a colonoscopy?

A colonoscopy is the gold standard for detecting colorectal cancer. The procedure is painless, but it gets a bad rap. Why?

Because, admittedly, the preparation to achieve a clean colon can be unpleasant. The prep involves drinking a prescribed liquid to clean out your colon over a 12-hour period.

During the procedure, the patient is asleep and feels nothing. A scope is used to look inside the colon for tumors or polyps. Polyps are an overgrowth of cells on the inner lining of the colon wall. They can develop into cancer, and your doctor may remove them during the colonoscopy. If left untreated, cancer cells can grow through the colon wall and can spread to other organs, which is why early detection is crucial.

If precancerous lesions are found during a colonoscopy, they are removed, reducing a patient’s colon cancer risk. So while the prep is no picnic, it is preferable to a potential cancer diagnosis.

Another preventative screening is a sigmoidoscopy – or Flex Sig. Like a colonoscopy, this procedure uses a thin flexible tube with a camera at the end to look at the colon. While colonoscopy examines the entire colon, sigmoidoscopy is a partial exam that only covers the left side of the colon.

At-home colorectal cancer screening

Although not intended to replace a colonoscopy, preliminary at-home screening tests like FIT and Cologuard are available for average risk patients. These at-home tests can help find colon cancer at an early stage when it can be treated, even before any signs or symptoms develop.

Your primary care physician can prescribe a fecal immunochemical test, or FIT Test, that you can complete at home and mail in a stool sample. FIT is available for average risk patients 50 and older and should be performed annually.

No dietary restrictions are required leading up to the testing period. FIT has highly accurate results since it detects only blood from the lower-GI tract where polyps and colorectal cancer develop. If a patient receives a positive test result, further evaluation is necessary. The American Cancer Society recommends following up with a colonoscopy.

Cologuard is another at-home cancer detection test for colorectal cancers. It identifies altered DNA and/or blood in stool, which are associated with the possibility of colon cancer or precancer. Cologuard is covered by Medicare every three years for average risk patients between 50 and 85. It is recommended to take the Cologuard test every three years.

Cologuard uses a molecular biology process to capture specific pieces of DNA for further analysis. A positive result may indicate the presence of colorectal cancer or advanced adenoma and should be followed by diagnostic colonoscopy.

Because it is possible to receive a false positive diagnosis when testing at home, it is important to discuss all screening options with your doctor before moving forward with the screening process.

Regular colorectal cancer screening is one of the most powerful tools for preventing colon cancer.

Colorectal cancer prevention

The best thing you can do to prevent and colorectal cancer is get regular screenings and know your risk factors.

There are some lifestyle changes you can implement to lower your risk for developing colorectal cancer. Those include:

• Maintaining a healthy weight
• Starting an exercise program
• Eating a healthy diet
• Limiting alcohol

Risk factors you cannot control include:

• A personal history of colorectal polyps or colorectal cancer
• A personal history of inflammatory bowel disease, or IBD
• A family history of colorectal cancer

Colorectal cancer is preventable. It's important that you don’t ignore your symptoms and are aware of your family history.