Colorectal Cancer

Learn about colorectal cancer, screening and diagnosis, treatment, and what to do next.

What is colorectal cancer?

Colorectal cancer is cancer that begins in the colon (large intestine) or rectum. Many colorectal cancers develop from growths called polyps. Some polyps can become cancer over time. Finding and removing precancerous polyps during screening can help prevent colorectal cancer. [1]

Colorectal cancer may not cause symptoms at first. That is why screening is important even when you feel well. Screening tests look for cancer or precancerous growths before symptoms begin. [1, 2]

Possible signs and symptoms

Contact a healthcare professional if you notice:

• A change in bowel habits—such as diarrhea, constipation, or narrower stools—that lasts more than a few days
• A feeling that you need to have a bowel movement that is not relieved after going
• Bright-red blood in or on the stool, or dark or black stool
• Ongoing abdominal cramps or pain
• Unexplained weight loss
• Weakness or unusual fatigue, which can sometimes be related to anemia

These symptoms may have causes other than cancer, but they should be evaluated. Do not assume rectal bleeding is caused by hemorrhoids. A screening test—even a recent negative one—does not replace evaluation of new or persistent symptoms. [3]

Get urgent medical care for heavy bleeding, fainting, severe or worsening abdominal pain, or vomiting with inability to pass stool or gas.

How do clinicians find it?

Screening when you have no symptoms

For adults at average risk, the American Cancer Society’s 2026 guidance recommends regular screening beginning at age 45. Adults in good health may continue through age 75; from ages 76 to 85, the decision should be made with a healthcare professional based on overall health, screening history, and preferences. Screening is generally not recommended after age 85. [2]

Screening options include:

• Colonoscopy: A clinician examines the colon and rectum with a flexible camera. Polyps can often be removed during the procedure. For average-risk screening, it is commonly repeated every 10 years if results are normal.
• Stool tests: Some are done at home and check for hidden blood or abnormal DNA/RNA markers. Depending on the test, they are generally repeated yearly or every 3 years.
• Other visual tests: CT colonography or flexible sigmoidoscopy may be options for some people, usually at 5-year intervals.
• Blood-based screening: A blood test is an option in some circumstances, but it is not a preferred option in current ACS guidance because it is less likely to find precancerous growths and some early cancers. [2]

Any abnormal result from a stool, blood-based, or other non-colonoscopy screening test needs timely follow-up—usually a colonoscopy—to complete the evaluation. Screening tests are intended for people without symptoms; symptoms may require diagnostic testing even if you are not yet due for routine screening. [2, 3]

People with a personal or family history of colorectal cancer or certain polyps, inflammatory bowel disease, or an inherited risk condition such as Lynch syndrome or familial adenomatous polyposis may need to start earlier or follow a different plan. Tell your clinician about your personal and family history so they can recommend an appropriate schedule. [2]

Testing when cancer is suspected

Your evaluation may include questions about symptoms and family history, a physical examination, blood tests, and a colonoscopy. During colonoscopy, the clinician may remove polyps or take a tissue sample (biopsy). A pathologist examines tissue under a microscope to determine whether cancer is present. [4]

If cancer is diagnosed, additional tests—often imaging and sometimes blood tests—help determine whether and how far it has spread. This is called staging. Tumor and hereditary-risk testing may also help guide treatment. [4, 5]

How is colorectal cancer treated?

Treatment is based on the cancer’s location and stage, test results, overall health, and your preferences. Your care team may include specialists such as a gastroenterologist, colorectal surgeon, medical oncologist, and radiation oncologist. [5, 6]

Treatment may include one or more of the following:

• Endoscopic removal or surgery: Some very early cancers can be removed during a procedure. Other cancers may require surgery to remove the affected part of the colon or rectum and nearby lymph nodes.
• Chemotherapy: Medicines may be given before or after surgery, or to treat cancer that has spread.
• Radiation therapy: Used more often for rectal cancer than colon cancer; it may be combined with chemotherapy and given before or after surgery.
• Targeted therapy or immunotherapy: These medicines may be appropriate for certain cancers, depending in part on tumor test results.
• Follow-up care: After treatment, appointments and tests help monitor recovery and check for recurrence. [5, 6]

A treatment plan is individualized. Ask your cancer care team about the goal of each treatment, expected benefits and risks, possible side effects, and whether a second opinion or clinical trial is appropriate.

What are the next steps?

• If you have symptoms: Contact a healthcare professional promptly for advice, even if you recently had a normal screening test.
• If you are 45 or older and have not been screened: Ask which screening option fits your health history and preferences.
• If a stool or blood screening test was abnormal: Arrange the recommended follow-up colonoscopy. A positive screening test does not by itself mean you have cancer.
• If you have a higher-risk history: Share details about relatives who had colorectal cancer or polyps, their age at diagnosis, your own polyp history, inflammatory bowel disease, and known inherited conditions.
• If you have been diagnosed: Ask for copies of your pathology and imaging reports, the cancer stage, whether tumor or genetic testing is recommended, and who will coordinate your care.

Call Digestive Healthcare of Georgia to set up an appointment with one of our providers.

Sources

1. National Cancer Institute (NCI). Colorectal Cancer—Patient Version and Colorectal Cancer Screening (PDQ®)—Patient Version. cancer.gov.
2. American Cancer Society (ACS). Colorectal Cancer Screening Guideline (2026) and 2026 Guideline Update. cancer.org.
3. American Cancer Society (ACS). Colorectal Cancer Signs and Symptoms. cancer.org.
4. National Cancer Institute (NCI). Colon Cancer Treatment (PDQ®)—Patient Version, diagnosis and staging sections. cancer.gov.
5. National Cancer Institute (NCI). Colon Cancer Treatment (PDQ®)—Patient Version. cancer.gov.
6. National Cancer Institute (NCI). Rectal Cancer Treatment (PDQ®)—Patient Version. cancer.gov.

This information is for general education and does not replace medical advice, diagnosis, or treatment. Your clinician can recommend care based on your individual situation. Screening recommendations may differ among organizations and may change; discuss your personal screening plan with your healthcare professional.