Most patients with colorectal cancer experience some form of physical side effects from the treatments they’ve received. The intensity and the specific types of side effects depend on a variety of things including how far the cancer has spread inside the colon or beyond, the type of treatments being given, and your overall health condition at the time of treatment. Plus, your side effects may also change from one treatment session to the next. 

At Rocky Mountain Cancer Centers (RMCC), we care deeply about our patients and listen to them to understand what they’re experiencing. We’ll do all we can to help them feel better and enjoy life as much as possible during cancer treatment. 

Common Side Effects Experienced During Colorectal Cancer Treatment

Here are some of the most common colorectal cancer treatment options and how you can help manage or even avoid them.

Download our free eBook with helpful tips for managing side effects and  planning for colorectal cancer treatment.

Loss of Appetite

Chemotherapy can cause nausea and vomiting. And no one wants to eat when they’re feeling sick to their stomach. But without drinking anything, you can become dangerously dehydrated, and without food you’ll start to feel exhausted and weak. 

Start with smaller and more frequent meals to regain your appetite. Take plenty of fluids and electrolytes. Avoid caffeinated drinks, sugary beverages, and alcohol as best you can until cancer treatment is complete.

There is often medication given with chemotherapy or sent home with you to use later to help minimize nausea. If you’re experiencing mouth sores from treatment, that can be addressed by the oncology team as well. Talk to your cancer care team about how you’re feeling so they can help with medication doses.

Change in Bowel Movements

Change in bowel movements (frequency of stools and consistency) is the most common side effect in colorectal cancer treatment.  

Because chemo and radiation are focused on your bowels, there can be a lot of impact here. You may experience moderate to severe diarrhea and dehydration. Your oncologist would prescribe anti-diarrhea medicines to keep the side effects in control. 

After colon surgery, the digestive tract takes time to come back to normal function. Introduce different food types at regular intervals to understand what best suits your system.  

Certain pain medications can cause constipation in patients. To control constipation, follow a fiber-rich diet and use stool softeners and over-the-counter laxatives if needed.

Abdominal Pain 

Abdominal pain during colorectal cancer treatment can occur because it affects how food and liquid move through the intestinal tract. Cramping can also occur during diarrhea or constipation. Chemotherapy can alter the bacteria in the intestines, which contributes to pain and flatulence (gas). 

Keep track of your pain levels and how frequently you are experiencing issues. You should describe your experiences with your oncologist. You can also try to maintain a simple diet that includes more fluids and less sugar. These foods are more easily digested and can help keep the pain under control. 


Free Guide for Newly Diagnosed Colorectal Cancer Patients

Get helpful tips on what to expect and how to prepare your mind and body for colorectal cancer treatment. 

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Just about every cancer patient feels fatigued while going through cancer treatment. It’s not just being tired. Fatigue is exhaustion to the point where you can’t function in your normal daily activities. Give yourself a break here. It should get better with time. In the meantime, plan activities based on your energy level and tell those who you might plan activities with that you may have to bow out. Follow a well-balanced diet to help increase energy levels and ask for help from your support network when you need it. 

Cold Sensitivity

Plan for cold sensitivity caused by the FOLFOX chemotherapy that's used for colorectal cancer. This may be surprising, but you get really cold really easily while taking this chemotherapy and in the 3-5 days following a chemo treatment. 

If you touch something cold like a cold soda can or items in the refrigerator, it can cause a burning sensation where your skin touched the cold items. There is no actual damage to the cells, but the burning pain can be quite uncomfortable. Eating or drinking cold or hot foods can feel like swallowing shards of glass.

TIP: Put a reminder sign on the fridge door and put gloves by the fridge. Put them on before coming in contact with cold objects. 

Some good news…Most people don't lose their hair as part of the FOLFOX colorectal chemotherapy treatment!


Higher Risk of Infection

Chemotherapy drugs kill both cancer cells and healthy cells, including those that keep your immune system strong. Your white blood cell count is being monitored by your cancer specialist quite often to keep you from an increased risk of infection during cancer treatment. You may be given shots that boost white blood cell production to help avoid infections during treatment.

Mucositis, for instance, is an infection that occurs for some colorectal cancer patients causing soreness and inflammation all along the digestive tract. It is a common side effect of chemotherapy and radiation therapy. 

If you should notice a fever, redness, or swelling anywhere in the body, call your cancer specialists right away. 

Changes in Appearance and Behavior

Side effects that can change your appearance: 

  • Problems with the digestive system and changes in diet can lead to weight loss. 
  • After a few sessions of radiation therapy, the skin around the treatment area becomes red and itchy. 

Because cancer and cancer treatments cause pain and discomfort, it can sometimes create an uneasiness that can be seen by those who know you best. Continually monitor and reflect on how you’re feeling. Identifying changes in your mood can be one of the first signs of a physical issue that your oncologist will need to address. 

Peripheral Neuropathy

Neuropathy is one of the long-term side effects of cancer treatment. Chemotherapy can affect the nerves that lie between the spinal cord and skin, and internal organs. This condition is called peripheral neuropathy. 

When the chemotherapy drugs affect the small sensory nerves of the feet and hands, you may feel a tingling sensation or numbness in the extremities. Sometimes, cancer drugs can damage nerves that control internal functions. 

Your oncologist can do a brief exam to test your sensitivity along with other lab tests and imaging tests. Based on the test results, the doctor will prescribe a tailored treatment plan with a physical therapist.  

Easy Bruising and Bleeding

Chemotherapy drugs destroy the quickly dividing cancer cells. However, they can also affect the blood-forming cells of the bone marrow. As a result, the number of blood platelets decreases. This leads to easy bruising and increased bleeding during cancer treatment.

Long-Term Side Effects of Colorectal Cancer Treatment

Your body needs time to heal after the end of colorectal cancer treatment. Fatigue and tiredness may stick around, even months after the treatment is completed, but it should gradually improve. Your bowel functions may also take time to come back to normal, especially if you had to have an ostomy for a period of time. 

If you feel overwhelmed or struggle with mental health issues during or after cancer treatment, talk to your doctor about it. Your cancer care team and other cancer support groups may be a good source of emotional support. 

Don’t Ignore Your Cancer Treatment Side Effects

There is often something that can be done to reduce your discomfort. Don’t just suffer through. You should talk to your oncologist and your nurse about what you’re experiencing. And if there is anything that causes you to be suddenly concerned, please don’t hesitate to call and ask.

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