Colorectal Cancer: Symptoms, Diagnosis, and Treatment


What Are Typical Colorectal Cancer Symptoms?

Colorectal cancer (CRC) might not cause symptoms immediately and screening is the most effective method to identify and remove polyps before they evolve into malignant disease. Speak to your doctor if you experience one or more of the following symptoms:

  • A change in bowel habits including diarrhea, constipation, or narrowing of stool that persists over a couple of days
  • Constant changing in bowel habits – e.g., feeling like there is bowel movement that is not relieved by passing stool
  • Rectal bleeding with visible red blood
  • Blood in the stool, which can change the appearance of stool to look dark brown or black
  • Abdominal cramping or pain
  • Weakness and fatigue
  • Inexplicable weight loss

It is important to remember that the signs and symptoms of CRC are similar to those found in common bowel conditions that are NOT cancer, such as IBD, ulcers or Crohn’s disease. More information on these signs and symptoms can be found on the American Cancer Society (ACS) and the American Society for Clinical Oncology (ASCO) websites. 

Understanding a CRC Diagnosis

CRC is diagnosed after the onset of symptoms or when a guideline-recommended preventive screening test is conducted. Information on types of screening tests can be found here. In addition to diagnosing CRC, doctors perform additional tests to understand whether the cancer has spread to another area of the body, known as metastasis. Your doctor will consider these factors when choosing an appropriate diagnostic method for you:

  • The primary location of the suspected cancer
  • Your symptoms and signs
  • Your age and health
  • Your medical and family health history
  • The results of your earlier screening tests

Both physical tests and the tests listed below may be used to diagnose CRC. Detailed information on these diagnostic tests can be found on the ASCO website:

  • Colonoscopy
  • Biopsy
  • Molecular testing of the tumor tissue
  • Blood tests
  • CT or CAT scan
  • MRI
  • Ultrasound
  • Chest x-ray to determine if the cancer has spread to the lungs
  • PET or PET-CT scan

After these diagnostic tests are performed, your doctor will review the results and determine whether your clinical symptoms are related to cancer. If the results indicate a cancer diagnosis, these tests will also allow your doctor to stage the cancer. Some additional tests may be performed to characterize the tumor and identify the best treatment options.

More information about the entire diagnostic process and details on the associated tests can be found in this ACS document.

What happens after a CRC Diagnosis?


Following a confirmed diagnosis, your doctor may recommend another series of tests to determine the extent of your cancer—this is called staging. Staging tests include abdominal, pelvic, and lung imaging scans. However, the stage of your cancer may not be fully determined until you undergo exploratory CRC surgery to remove the cancer, in parts or whole.

CRC stages range from 0 (very early CRC) to IV (advanced stage CRC). As a rule of thumb, the lower the number, the less the cancer has spread. A higher number like stage IV, is when CRC is considered to have spread (metastasized) to other sites (organs) the body. The staging system most commonly used for CRC is the American Joint Committee on Cancer (AJCC) TNM System, which is based on:

  • The size of the tumor (T)
  • The spread to the surrounding lymph nodes (N)
  • The spread (metastasis) to distant sites (M)

Detailed information on staging can be found on the ACS website and the staging chapter (pages 30-35) of Cancer.Org CRC PDF.

Understanding Your Pathology Report

A pathologist evaluates tissue (biopsy) samples, including your colon and rectal tissue samples removed during surgery or a biopsy. The findings are then written up as a Pathology Report. It contains important information about your tumor and is used to decide the best treatment option for you. You should request a copy of this report and bring it to your treating doctor to better understand your CRC diagnosis.

Below are a few resources that can help decipher the contents of your Pathology Report:

Speaking to Your Loved Ones About Your Diagnosis

A cancer diagnosis can be extremely overwhelming for you as well as for your family and friends. People often are at loss for words, and do not know how to come to terms with this news. They may feel upset and angry; others may find it easier not to talk about it due to fear of saying the wrong thing or confronting the possibility of losing you.

So, how do you talk about your diagnosis with your loved ones? While there is no standard answer to this question, there are a few things you could do to help break this news to your loved ones. Your feelings about your diagnosis are important. Naturally, you will have many emotions centered around your diagnosis, treatment options, and prognosis. It is perfectly normal to wonder ‘Why me?’ The first step is to admit your feelings about your diagnosis to yourself and to allow yourself to feel the way you do. Only you can decide when you are ready to talk about your cancer and how much you want to share. Then, make a list of the people you would want to share this with. The following resources can help you prepare for this conversation:

Speaking to others about your cancer diagnosis can be overwhelming. You should consider participating in support groups or speak with a trained therapist to gain the comfort you seek.


Typically, the course of treatment for a cancer patient is developed by a team of doctors who weigh different factors to determine the overall treatment plan, which tends to combine different treatments. This group of doctors is called a multidisciplinary team (MDT). For CRC, the MDT generally includes a surgeon, medical oncologist, radiation oncologist, and a gastroenterologist (a doctor specializing in disorders of the gastrointestinal tract). These MDT teams also work with an array of other health professionals including but not limited to physician assistants, nurses, oncology nurses, social workers, pharmacists, counselors, and dietitians.

The common treatment options for CRC are listed below:

  • Surgery – Removal of the tumor and some of the surrounding healthy tissue during an operation. Surgical options include:
    • Laparoscopic surgery: small incisions, shorter recovery time
    • Colostomy for rectal cancer: a surgical opening for waste removal that may be temporary or permanent
    • Radiofrequency ablation or cryoablation for tumors that have spread to the liver or lungs
  • Radiation Therapy (radiotherapy) – The use of high energy x-rays to target and destroy cancer cells,
    • External beam radiation therapy
    • Stereotactic radiation therapy
    • Intraoperative radiation therapy: radiation given during surgery
    • Brachytherapy: radioactive “seeds” placed in the liver if the cancer has spread to the liver
    • Chemoradiation: a combination of chemotherapy and radiation therapy (chemoradiation) is recommended for rectal cancer before surgery
  • Chemotherapy – The use of a single or combination of drugs to destroy or kill cancer cells, usually done by inhibiting cancer cell growth, division, and replication.
  • Immunotherapy – Designed to boost the patient’s own immune system (natural defenses) to fight cancer. It tends to use material either produced by the body or in a lab to improve, target, or restore the function of the immune system.
  • Targeted therapy – Treatment targeting cancer specific genes, proteins, or the environment of the cancer. It tends to block the growth and spread of cancer within the body while limiting damage to the healthy tissue.

It is important to remember that your treatment plan will depend on your cancer (particularly its stage) and that your care plan may also include symptomatic treatments, which are important to improve your quality of life. Additionally, every treatment is associated with its own side effects so it’s crucial to research your options and understand what you want from CRC treatments. Detailed information on each of these treatment options can be found on the American Society of Clinical Oncology and American Cancer Society websites.

Talking to Your Doctor About Your Treatment Options

The following factors influence the treatment strategy:

  • Stage and grade of the cancer
  • Side effects of treatments
  • Patient’s preferences concerning their overall health

It is crucial to invest time in learning about all your treatment options and ask questions about aspects that are unclear. Talking with your doctor and developing a strong relationship with your MDT are important to develop a personalized treatment plan. Shared-decision making is important to meet your goals of care. Here are some resources that highlight important questions you can ask your doctor:

Remember: you rely on your doctor to be clear and transparent about your diagnosis and to provide you with resources that guide your decision making and care. Your doctor, in turn, relies on you to be open and honest about what you are experiencing and your expectations. You need to work as a team to receive the best care possible that meets your goals.

Mental Health and Cancer

A cancer diagnosis can affect you and your family’s mental health. It can lead to depression, distress, anxiety, and stress, in turn influencing your daily life. Below are a few resources that can help cope:

Your mental health can greatly influence treatment outcomes. Therefore, it is vital that you understand and recognize these negative emotions and seek help. Help can come in many forms—whether it be therapy, support groups, or counseling—and can assist you through diagnosis, treatment, and beyond. Here are a few of these resources:

Ostomy Support Groups:

Psychosocial Support for Young Adults:

Long-Term Care and Survivorship

What is cancer survivorship? You will find several definitions or descriptions for the terms ‘cancer survivor’. The most common definition is a person who is in complete remission—meaning no signs or symptoms of cancer following the end of treatment. The National Cancer Institute, however, describes everyone diagnosed with cancer as a survivor “through the balance of his or her life”. This definition includes the survivor’s family, friends, and caregivers as well.  

Cancer survivorship, which begins at diagnosis can be categorized into the following stages:

  • From diagnosis to the end of initial treatment
  • The transition from treatment to extended survival
  • Long-term survival

Survivorship can be one the most complicated and challenging aspects of having/living with cancer, because it is unique to every patient and involves emotional, mental, psychosocial, and physical factors. Survivors may feel a whirlwind of emotions including guilt and unease when their frequent health visits become infrequent as their treatment nears end. Every survivor may have a unique way of coming to terms with their survivorship, but it may be helpful to consult resources that could guide you through your journey. These resources can help set expectations and prepare you to face the long-term impact of your diagnosis and treatment:


Recurrence may be local or distant.

Local Recurrence: When the cancer returns at the original site, it is classified as local recurrence and may be characterized by:

  • Changes in bowel habits
    • Less frequent bowel movements
    • Narrow stools
    • Hard stools
  • Obstruction
    • Abdominal bleeding
    • No bowel movements
    • Abdominal pain
    • Vomiting
    • Increase in size of the abdomen

A colonoscopy may be needed to detect any recurrence that is inside the colon. However, if the recurrence is outside the wall of the colon, it will not be visible by colonoscopy, but may need a CT scan or tumor marker test (CEA levels). Local recurrence is usually treated with another surgery. Colon cancers are usually easier to remove, but complications may arise with local recurrence of rectal cancer, especially if adjacent organs are involved. Radiation therapy may be recommended, and the surgeon may need to remove other organs.

Distance Recurrence: Liver and lungs are the most common sites of distant CRC recurrence. They usually lack specific symptoms and may be diagnosed after a follow-up CT scan or abnormal levels of CEA protein. Chemotherapy would be the most likely line of treatment for distant recurrence.

Follow-up Care

Follow-up care will depend on your specific treatment. It is important that you understand these guidelines and that you follow through with them as they are vital to maintaining your quality of life and for ensuring your best health.

Cancer patients often require long-term monitoring for adequate management of treatment-related side effects, late-effects that may emerge, and recurrence, meaning the cancer comes back, often within the first five years of treatment. You should speak to your doctor about what a follow-up care plan will look like for you.

Recommendations for Stage II/III CRC

  • Regular physical exams every three to six months
  • Clinical exams to monitor recurrence:
    • Tumor marker testing: CEA protein levels may be monitored every three to six months for five years
    • Computed Tomography or CT scan: These are 3D x-rays of the inside of your body, usually abdomen and chest, recommended annually for three years. Your doctor may recommend a CT scan every six to 12 months if you are at a high risk of recurrence. For those who had rectal cancer, a pelvic CT scan may be recommended.
    • Colonoscopy: This test allows the doctor to view the rectum and colon with a flexible tube called a colonoscope. It may be performed after a year of surgery but is typically recommended once in five years.
    • Rectosigmoidoscopy: Similar to a colonoscope, a flexible tube is inserted into a patient’s rectum to check the area for polyps or cancer. For those who were not treated with radiation therapy following rectal cancer, a rectosigmoidoscopy is recommended every six months.

Follow-up care varies for patients who have had surgery for metastatic colorectal cancer (CRC) or those who have inherited CRC. Since there is no clarity around follow-up testing for those who had stage I CRC, its best to speak with your care provider.

Specific information on yearly treatment plans can be found here.

Here are some additional resources for follow-up care:

Financial, Transportation, and Navigation Resources

Healthcare is expensive and cancer care particularly so. Financial stress and hardships after a cancer diagnosis and throughout treatment have been well-documented in the U.S. Over 50% of cancer survivors report being stressed about paying high medical bills or have delayed medical care due to high costs.

Research shows that cancer patients spend more out of pocket for their medical care than their counterparts without cancer, which can lead patients and their family towards what is known as ‘financial toxicity’. It can also compound as negative physical and mental health effects and can impact patients’ quality of life and treatment outcomes.

Treatment Costs

Colorectal cancer is one of the most commonly diagnosed cancers in both men and women in the U.S. A recent study comparing the colon cancer treatment costs between insurance-based benefit schemes and care sources within the US Military Healthy Systems (MHS) highlighted that the median cost of colon cancer treatment was $60,321 regardless of the care scheme. Considering the high cost of care, it is important to be well informed when discussing treatment options with your multidisciplinary care team. It could also be advantageous to research the average cost associated with each treatment option made available to you. Here are some resources that could help you understand the cost of cancer care:

Financial Resources

Various resources for cancer financial aid are available that assist with cancer treatment, hospital stay, as well as non-medical costs such as grocery and utility bills. Here are a few:


Children and Young Adults

Federal and State Benefits

Cancer patients who need to go on disability because they cannot work—either due to their cancer, the treatment, or because of after effects—may be eligible for Social Security Disability Income or Supplemental Security Income.

Fertility and Family-Building

Food Insecurity

  • MealTrain to organize meals for a friend after a birth, surgery, or illness


Transportation can pose a significant challenge for a patient who may need help getting to and from their cancer treatment site, because they may not be able to drive themselves and family caregivers may not be able to take time off from work. Here are some options:

Patient Navigators

Many hospitals have patient navigators who can help you identify additional sources relevant to you and your diagnosis. Patient navigators help:

  • Guide patients through screening, diagnosis, treatment, and follow-up
  • Set up appointments with doctors and for medical tests
  • Communicate with the patient’s care providers
  • Connect patients with financial, legal, and social support

Most major health systems and hospitals have a patient navigation program. Find out more by speaking to your oncologist, your multidisciplinary care team member, or by enquiring at your hospital or treatment center.