Constipation From Chemotherapy & Opioids

This page is for people who are constipated from chemotherapy or pain medicine. It starts with when to call your team, then explains why it happens, what helps, and which medicines are used.

Tell your doctor or nurse if you are having constipation, so you can get treatment as soon as possible. Report it if you are having fewer than three bowel movements in one week.

Do not wait it out if things escalate. NCI warns that chronic constipation can lead to fecal impaction or bowel obstruction. Both are potentially life-threatening, and NCI says they need immediate medical care.

• Call 911 or go to the nearest emergency department if you suddenly cannot urinate at all, you are suddenly confused or hard to wake, or you have trouble breathing. NCI lists these among the signs of fecal impaction.
• Call your care team right away if you have severe stomach pain along with vomiting, or other signs of fecal impaction, such as pressure in the rectum with leaking stool or sudden watery diarrhea. Do not try another laxative at home. If you cannot reach your team quickly, go to the nearest emergency department.
• If you are getting chemotherapy, call your care team right away, day or night, if you have a temperature of 100.4°F (38°C) or higher, chills, or you feel unwell. CDC says an infection during chemotherapy can be life-threatening. A normal temperature is not a reason to wait.

Also contact your doctor or nurse if you are having side effects from your pain medicine. NCI advises calling if new pain appears, if pain is not decreasing with the medicine, or if you have side effects from it, including constipation. NCI says pain is not something you have to put up with.

Constipation is common during cancer treatment, and your doctor can recommend ways to treat it. You may be unable to have a bowel movement, need to push harder, or have fewer bowel movements than usual. NCI says constipation may be short-term or chronic.

NCI lists several reasons people with cancer become constipated.

• Certain cancers. Colon, rectal, and ovarian cancers and brain tumors can block the movement of stool through the bowel, or affect the spinal nerves that control it.
• Cancer treatment. Chemotherapy can cause constipation as a side effect.
• Medicines. Opioid pain medicines, antianxiety medicines, antinausea medicines, and diuretics can all slow the bowel.
• Changes in daily life. Moving around less and eating differently than usual both contribute.

Opioids deserve special mention. NCI's page on cancer pain notes that common side effects of pain medicine include constipation, drowsiness, nausea, or vomiting, and that some of these may go away as your body gets used to the medicine. It does not say which ones, or how long that takes. NCI also says that if your doctor expects constipation, they will give tips and prescribe medicine to prevent it. So it is worth asking whether to manage it from the day the medicine starts rather than waiting to see.

According to NCI, signs and symptoms include:

• Having two or fewer bowel movements in one week.
• Dry, hard, or lumpy stool.
• Pain during a bowel movement.
• Difficulty having a bowel movement.
• Stomach pain or cramps.
• Feeling bloated or nauseous.

NCI suggests keeping a record of your bowel movements, so your team can see what is usual for you and what has changed.

NCI's practical advice is short and specific.

• Drink plenty of liquids. Drinking 8 cups of water or clear liquids per day can help.
• Try to be active every day. Walking, biking, yoga, or exercises done in a bed or chair all count.
• Eat at the same time each day. A regular schedule helps the bowel keep a rhythm.
• Keep a record of your bowel movements, so your team can see what is normal for you and what has changed.
• Ask your doctor about dietary fiber. This one is not automatic. NCI notes that high-fiber foods and fiber supplements can make constipation worse for some people with cancer, so check before you add them.

Use only the products your doctor recommends. NCI describes three types used for constipation: osmotic laxatives, stool softeners, and stimulant laxatives. Examples include polyethylene glycol, docusate, and bisacodyl. Your team will pick based on your treatment, your blood counts, and your other medicines.

One safety point from NCI is worth reading twice. Do not use suppositories, which are capsules you insert into your anus, or enemas, which are liquid medicine you inject into your anus, unless your doctor recommends them. In some people with cancer, these treatments may lead to bleeding, infection, or other harmful side effects.

• Which of my medicines are likely to cause constipation, and should I start a bowel regimen now?
• Which laxative or stool softener do you want me to use, at what dose, and how often?
• How many days without a bowel movement should prompt a call to you?
• Should I be adding fiber, or would that make things worse for me?

• National Cancer Institute — Constipation and Cancer Treatment: https://www.cancer.gov/about-cancer/treatment/side-effects/constipation.
• National Cancer Institute — Cancer Pain: https://www.cancer.gov/about-cancer/treatment/side-effects/pain.
• CDC — Watch Out for Fever: https://www.cdc.gov/cancer-preventing-infections/patients/fever.html.