Colorectal Cancer: Signs, Symptoms and Screenings

What to know about colorectal cancer.

The American Cancer Society reported that approximately one in 23 men will develop colorectal cancer (cancer of the large intestine) during their lifetime. Women have a slightly lower risk, with about one in 25 expected to be diagnosed with colorectal cancer.

Furthermore, experts predict that they will diagnose over 150,000 new cases of colorectal cancer in 2024. This type of cancer is the third most common across the globe.

The World Health Organization said it is the second top cause of cancer deaths in the US. This means that it is a significant factor in many deaths in the country. Cancer is a serious health issue that affects many people.

Understanding Colorectal Cancer

Colorectal cancer is found in the colon or rectum. Certain types of polyps in the large intestine can develop into cancer; however, many polyps detected during screenings often are benign (non-cancerous).

Polyps grow slowly in the intestine lining, underscoring the importance of screening to remove cancerous ones. Additionally, rising rates of colorectal cancer in younger adults further emphasize the importance of routine screening.

The most common type of colorectal cancer is adenocarcinoma. Carcinoid tumors, gastrointestinal stromal tumors, lymphomas and sarcomas are other types of tumors that doctors may find in this region of the body.

Finding polyps early is crucial to preventing cancer. Identifying them in the early stages makes it easier to remove them safely and avoids more invasive surgeries.

Polyps often lack signs or symptoms, so it is more common for physicians to diagnose colorectal cancer at more advanced stages. Regular screening tests like stool tests and colonoscopies are important for finding problems early and getting treatment.

Five Facts About Colorectal Cancer

Whether you are investigating for yourself or a loved one, understanding colorectal cancer can be both confusing and overwhelming. You should keep a list of questions and concerns to discuss with your physician. However, as you look into the diagnosis, here are several details.

  1. The medical community has accepted colorectal cancer as an umbrella term.
    Is colorectal cancer, colon cancer and rectal cancer the same or different, and why are they often grouped? Colorectal cancer starts in the large intestine. Colon cancer starts in the colon lining and rectal cancer starts in the rectum tissues. The rectum is the lowest 12 centimeters of the large intestine.
    Colon and rectal cancers are grouped together as colorectal cancer because they are detected through similar tests and are treated with somewhat similar medications.
  2. Physicians give cancer the name based on where it starts.
    Cancer that spreads to other parts of the body, a process called metastasis, involves other organs throughout the body. If the cancer spreads, the cancer name does not change. For example, if cancer starts in the colon lining and spreads to other parts of the body, physicians still call it colon cancer.
  3. Colorectal cancers begin as polyps.
    As explored earlier, polyps form in the lining of the intestine, whether that is in the large intestine or rectum. Colon cancer and rectum cancers both begin as polyps.
  4. Physicians screen for colorectal cancers using the same method.
    These cancers are often screened using the same methods. One popular method is colonoscopies. This method leverages a small camera at the end of a flexible tube, allowing the physician to look inside the rectum or colon to identify cancerous polyps. Additional testing to confirm the diagnosis, such as a biopsy, may be required.
  5. However similar, these cancers are different.
    Although these tumors may undergo similar screening and exhibit similar symptoms and signs, their treatments may vary. For example, some treatments for colon cancer may not be used for rectal cancer in the treatment plan.

Causes and Risk Factors

The risk of colorectal cancer increases as you age. It has been more common in people 65 years of age and older, with an average diagnosis at age 70.

The American Cancer Society lists other risk factors as obesity, type 2 diabetes, unhealthy diets (such as those high in red and processed meats), smoking and alcohol use.

Additionally, certain unchangeable factors can increase your risk, including racial and ethnic background, personal medical history, and family history.

Signs and Symptoms

Polyps grow slowly over time before potentially becoming cancerous, often without causing immediate signs or symptoms. Colorectal cancer can appear in various ways. These include blood in stool, changes in bowel habits, stomach pain, weight loss and low iron levels.

Other medical conditions also exhibit association with these symptoms, so it is important to consult your physician if you experience any of these issues.

Early Detection

According to the American Cancer Society, polyps can take 10 to 15 years to become cancerous. This slow growth and lack of symptoms illustrate why colorectal cancer can develop silently.

Finding issues early can increase survival chances. Screenings are important for catching problems early and improving outcomes.

Tell your physician about any irregularities to catch cancer early and have access to more treatment options if needed. Preventive care is key.


Two main cancer screening approaches detect colorectal cancer: stool-based tests and visual exams. Stool tests, which is a less invasive option, analyze stool samples for polyps that are cancerous and can be done at home instead of in the hospital or doctor’s office.

Visual exams allow physicians to directly view the colon’s interior, typically through colonoscopies. The American Cancer Society recently lowered the recommended starting age for screenings to 45 due to rising cancer rates in younger adults.

Colonoscopies use a flexible tube with a tiny camera at the tip. During the procedure, the physician inserts the tube through the rectum to examine the entire colon’s lining for polyps. The test itself takes about 15 minutes.

Sigmoidoscopies, another visual exam option, only examine a smaller portion of the colon and are not as widely used as colonoscopies. Another visual exam is a CT colonoscopy, which takes a CT scan of the colon and rectum to identify any abnormalities.

If screenings detect cancer, your physician’s next pivotal task is to identify the stage of the disease. The stage, a critical component in guiding treatment decisions, encompasses a range from stage 0 to stage IV, denoting the extent to which the cancer has spread within the body.

This identification is the foundation that allows the physician to create a targeted and personalized treatment plan that is right for you and your cancer diagnosis. While people have been diagnosed with the same cancer, each malignancy and tumor are distinct, requiring a customized treatment approach.

Related: Cancer Screenings: What You Need to Know

Therapies and Treatments

Many treatments are available for colorectal cancer patients, depending on the type of tumor and stage of the disease. Your physician may advocate for particular treatments because they are more tailored to your unique case. These treatments range from surgery to remove cancerous growths, to radiation, chemotherapy and targeted therapy drugs.

Questions to Ask Your Physician

Collecting questions regarding your diagnosis can empower you to make well-informed health decisions. Here are some questions to consider asking your physician and care team:

  • What is my diagnosis?
  • Where is the cancer located, and has it spread?
  • What is the stage of cancer, and what does that mean?
  • What are the treatment options for me?
  • How quickly do I need to decide on a treatment?
  • How long is the treatment, and what will it be like?
  • Does this treatment affect my fertility if I plan to have children?
  • Will this treatment affect my daily activities? What will I not be able to do during treatment?
  • What symptoms and side effects are there?
  • How often will I need to visit you during treatment?
  • What do you recommend based on your expertise?
  • What should I do to plan for treatment?
  • If I have transportation concerns, is there help available to get me to and from my treatment?
  • What are the chances that this treatment will cure the cancer?
  • Will I be able to continue working during treatment?

Related: How to Make the Most Out of Your Oncology Appointment

Understanding the complexities of colorectal cancer is essential. Knowing more about the disease, its symptoms, tests and therapies can empower you to manage your health journey.

It may feel daunting initially, but gaining knowledge is key. Taking control of your health starts with educating yourself. Do not let the amount of information discourage you.

Equipping yourself with the questions you have fosters a collaborative approach to your care, empowering you to actively participate in your journey toward recovery. While the journey may present challenges, there is a wealth of support and resources available to guide you and your loved ones.

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