Constipation is an infrequently mentioned chemotherapy side effect that can have a major impact on quality of life. Chemotherapy-induced constipation (CIC) is the third most common symptom in people undergoing chemotherapy. It affects approximately 16 percent of individuals with cancer. Some people find that they alternate between diarrhea and constipation. Others experience constipation only when they are on certain medications.

Let your health care team know if you experience new or worsening constipation. Keep in mind that there are many ways to help relieve constipation caused by chemotherapy.

Why Does Chemotherapy Cause Constipation?

Constipation occurs when your bowel movements are less frequent than normal or become difficult to pass. This can happen for several reasons, including dehydration and problems with movement of stool through the bowels.

Oncology researchers are not entirely sure why chemotherapy drugs cause constipation in some people. It is believed that these medications may lower the amount of liquid released in the bowel. Or, they may interfere with intestinal movement so that stools cannot form and move properly. A few chemotherapy drugs are also known to affect the nerves around the gastrointestinal tract. These drugs can influence how the intestines work and may lead to constipation.

Researchers have noted difficulties in distinguishing chemotherapy-induced constipation from secondary constipation. Drugs used to manage other chemotherapy or cancer-related symptoms (such as opioid pain medications) may cause secondary constipation. Additionally, being diagnosed with cancer or dealing with cancer treatment can change a person’s eating, drinking, and exercise habits. Changes in diet, being less active, and not drinking enough fluids may all cause constipation on their own — even without chemotherapy drugs.

What Is Chemotherapy-Induced Constipation?

The severity of chemotherapy-induced constipation varies from person to person. It also depends on the type of treatment you receive. Constipation can range from mild discomfort to significant abdominal pain and cramping. In some cases, these symptoms may improve as you adjust to treatment. Most side effects, including constipation, subside when treatment ends.

Generally, constipation may cause your stools to be small, hard, dry, and difficult to pass. You may also experience additional symptoms, including gas, bloating, stomach cramps, and nausea. As one MyLeukemiaTeam member shared, this can be severe: “I’m in a lot of pain. My digestive system is very slow.”

The particular response you have to your chemotherapy medications may not be the same as that of someone else with leukemia taking the same drug. In response to a MyLeukemiaTeam member who mentioned dealing with nausea while on a certain medication, another member wrote, “I don’t have nausea, but I deal with horrible constipation!”

Many people undergoing chemotherapy also deal with constipation alongside diarrhea. One MyLeukemiaTeam member shared, “I go back and forth between constipation and diarrhea,” while another wrote, “I get constipation or the reverse from my cancer treatment medications.”

Managing Chemotherapy-Induced Constipation

As always, talk to your doctor if you experience new or worsened constipation. You should not start taking new medications — even over-the-counter drugs — without talking to your doctor. Aside from any doctor-recommended changes or additions to treatment, the following suggestions may help you manage constipation caused by chemotherapy drugs.

Stay Hydrated

Dehydration can cause or worsen constipation. Make absolutely sure that you are getting plenty of liquids every day. Do not eat or drink anything that will dehydrate you. The Leukemia & Lymphoma Society recommends trying prune juice or drinking warm liquids in the morning if you’re experiencing constipation.

Talk to your care team about how much water you should be drinking on a daily basis. This conversation is especially important if you feel like you are drinking less than you used to or less than you should. Avoid alcohol and caffeine, as these can both cause dehydration.

Change Your Diet

Fiber can help prevent constipation. As one MyLeukemiaTeam member wrote, “I never get constipated because I tend to eat lots of high-fiber foods, like whole-wheat bread and pasta and veggies.” Another wrote that green olives help settle their stomach: “About six every night helps keep constipation at bay.”

The Leukemia & Lymphoma Society recommends gradually increasing your fiber intake with whole fruits, vegetables, beans, legumes, and whole grains. According to one study in Cancer Nursing, people experiencing constipation as a result of chemotherapy for leukemia found relief from eating sweet potatoes.

Ask your cancer care team how many grams of fiber you should eat each day. Your providers may recommend taking a fiber supplement, stool softener, or laxative to help relieve symptoms. You may also want to ask for a referral to a registered dietitian, who can create a dietary plan tailored to your needs.

Get Physical Activity

Moving your body stimulates bowel motion, too. You don’t have to exercise hard, but intentionally moving your body can improve chemotherapy-related constipation. The National Cancer Institute recommends walking for 20 to 30 minutes each day to help relieve constipation.

Medication

Taking a stool softener might help relieve persistent constipation. Unfortunately, this can go too far and cause diarrhea. As one MyLeukemiaTeam member noted, “My husband was constipated. He was up at 3:30 a.m. with the feeling that he had to have a bowel movement. Then, the medications he took for that gave him loose bowels.”

Finding a balance that involves the right levels of the right medications is important when it comes to battling constipation. With time and a dedicated medical team, it’s possible to find a combination that does both. As one of our members noted, “Now, I take an over-the-counter stool softener and have been a hundred percent better!”

If possible, avoid harsh laxatives, suppositories, or enemas — although these may become necessary if your constipation becomes particularly severe. Instead, try something that will be easier on your gastrointestinal system and your rectum. Your health care provider can make recommendations if you’re not sure where to start.

Get Support Today

MyLeukemiaTeam is the social network for people living with leukemia and their loved ones. Join us today to connect with people who understand the leukemia journey and meet others who will walk alongside you, offer advice, and answer your questions based on their own experience.

Have you experienced constipation as a side effect of your chemotherapy? You’re not alone. Share your story and let others know what’s helped in the comments below or by starting a new conversation thread.