Common Side Effects of Colon Cancer Treatment

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Treating colon cancer can save your life. But, treatment is not without side effects. The type of side effects you have and their intensity may differ from someone else's. They vary based on the kind of treatment you have and your overall health. Also, everyone experiences side effects differently. Your cancer care team is very familiar with all of these side effects. The good news is there are many effective ways to manage side effects to help you stay comfortable while you battle colon cancer.

Side Effects of Surgery

Many people need surgery to treat colon cancer. There are many ways to do the surgery. But, the surgery usually removes the area of the colon where the cancer is and some surrounding healthy colon tissue. Some of the most common side effects from this are pain, fatigue, and feeling sick to your stomach. You may notice swelling, tenderness or bruising in the area where the surgeon made the incision.

You may need to change your diet after colon cancer surgery because you may have trouble digesting some types of food. But, your body needs plenty of nutrients to heal from surgery and your cancer. Your doctor will talk with you about changes you should make to your diet to make sure you get the right nutrients as you recover. Your care team should give you a list of foods to eat and what to avoid in the days and weeks after surgery.

Side Effects of Chemotherapy

Chemotherapy drugs destroy your cancer cells. Sometimes they destroy healthy cells, too. Different chemotherapy drugs have different effects. Ask your oncologist what to expect with the drug(s) you are taking.

Common side effects of chemotherapy include:

  • Fatigue. Feeling very tired is one of the most common side effects. That's because the chemo destroys your red blood cells. Fatigue peaks the first few days after a round of chemotherapy and then it gets better until the next round.

  • Hair loss. Most, but not all chemotherapy drugs and drug regimens cause hair loss.

  • Mouth sores, nausea, and vomiting. All of these problems can make you lose your appetite after treatment. If these side effects become a problem for you, tell your doctor because there are effective treatment options.

  • Nerve damage (neuropathy). This can cause numbness and possibly pain in some parts of your body. Neuropathy may be temporary or permanent.

  • Diarrhea. Diarrhea makes you lose fluids, so you need to avoid dehydration when you have diarrhea. Drink clear liquids and foods you would normally eat to help with diarrhea, such as white rice and bananas.

  • Bleeding or bruising easily. Chemo also destroys platelets, which are the cells that help your blood clot so you stop bleeding. You will have blood tests to check your platelet count. Ask your doctor what symptoms to look for and when to seek medical help.

  • Infection. You might get sick more often with common infections because chemotherapy can impair your immune system. Be extra vigilant to avoid getting sick, such as frequent hand washing and staying away from large public places.

Side Effects of Radiation Therapy

Radiation therapy uses particles of ionizing radiation to destroy cancer cells in a specific spot in your body. After a few sessions, you may notice you feel very tired. Sometimes, people develop a reaction on their skin where the radiation was given. Your skin may feel red, itchy or dry. You may also notice that you need to have bowel movements more often than usual, or develop diarrhea. Some people lose their appetite.

Your doctor and cancer care team can help you manage these side effects so you can stay as comfortable as possible during your radiation treatment.

Long-Term Side Effects

Although many cases of colon cancer have a good cure rate, side effects may bother you long after you finish treatment. It takes time for your body to heal from cancer treatment. The most common long-term side effect of cancer and cancer treatment in general is fatigue.

Long-term side effects of colon cancer depend on where you had the treatment, what kind of treatment, and your physical and mental health prior to your diagnosis and treatment. In general, long-term side effects tend to be worse after rectal cancer. The rectum is the last part of the colon. The main concerns are bowel dysfunction, neuropathy, and emotional problems.

Treatment for cancer localized to the rectum can lead to bowel dysfunction. You may have trouble controlling your bowel movements (incontinence). Diet and antidiarrheal medicines can help manage bowel movements. Cancer treatment sometimes causes problems with urination, sexual function, and reproduction as well.

Chemotherapy can lead to long-term neuropathy lasting several months or longer after stopping treatment. It’s also possible to develop high blood pressure from taking certain chemotherapy drugs, but it usually responds well to medication.

Cancer and cancer treatment can take a toll on your mental health. Many people struggle with emotional issues, including anxiety, guilt, loneliness and depression. Talk with your doctor if you are feeling overwhelmed. You may want to consider joining a cancer support group.

Your follow-up care should include discussing and treating these long-term side effects so you can be healthy and happy long after your colon cancer is gone.

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Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2020 Feb 28
THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.

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  9. The Challenges of Colorectal Cancer Survivorship: Late and Long-Term Effects of Treatment. Medscape.