How to Manage Diarrhea

A guide for people with cancer.

What is diarrhea?

Diarrhea is loose, watery or unformed stools (poo) that might look like many small flakes or pieces. Diarrhea may also:

Happen more than three or four times a day
Cause an urgent need to go to the bathroom
Start during or after your cancer treatment
Last for a few hours or for a long time
Come and go over the course of your treatment
Go back and forth between constipation and diarrhea, especially if you are getting chemotherapy

When you have diarrhea, you may also feel:

Bloated and have stomach cramps (pain in your belly)
Restless or agitated (not able to stay calm or still)

Diarrhea can be a sign of a serious problem when you are getting immunotherapy. Contact your health-care team right away if you get diarrhea during immunotherapy treatment.

What causes cancer-related diarrhea?

Medications and treatments are the most common causes of diarrhea when you have cancer Some examples of medications that can cause diarrhea include:

Chemotherapy medicines like irinotecan and 5-fluorouracil (5-FU)
Cancer surgery
Radiation treatment to the pelvis (the area between your hip bones)
Medications like laxatives, antibiotics, metoclopramide, domperidone and antacids with magnesium
Immunotherapy like ipilimumab and nivolumab

Herbal medicines and natural health products can cause or worsen diarrhea. Some should not be taken when you are getting cancer treatments. Talk to your health-care team before taking any herbal medicines or natural health products, especially saw palmetto, ginseng, milk thistle, plantago seed, senna or cascara.

When should I talk to my health-care team?

Contact your health-care team if you have any of the following symptoms:

You have diarrhea:
- More than seven times in one day (24 hours)
- For more than 24 hours after you have taken medication to stop it
Blood in your stool (poo)
Pain in your abdomen (belly) that is not cramping from the diarrhea
You cannot eat or are afraid to eat
Signs of dehydration, which can be caused by diarrhea and vomiting:
- Being more thirsty than usual
- A dry mouth and tongue
- Dark yellow urine (pee) or passing very little pee
- Fatigue (feeling very tired) or dizziness
- Vomiting (throwing up)
- A fast heart rate

Go to the nearest emergency department if any of the following apply:

You have the symptoms in the list above and cannot reach your health-care team
You develop a fever while you are getting cancer treatment
- A fever is a temperature taken by mouth of:
  - 38.3 C (100.9 F) or higher at any time, or
  - 38 C (100.4 F) or higher for at least one hour

What can I do to manage diarrhea?

Take medication to stop or slow the diarrhea

Your health-care team may recommend loperamide (Imodium) to help control your diarrhea. For safety reasons, always check with your health-care team before taking loperamide.

Always follow your health-care team’s direction for taking diarrhea medication. Your health-care team may give you different directions for how to take diarrhea medication than what is written on the medication box.

Drink plenty of liquids to avoid dehydration

Your body loses a lot of liquid and electrolytes when you have diarrhea. Electrolytes are salts and minerals that your body needs to function properly. To help prevent dehydration when you have diarrhea:

Drink six to eight cups of liquids a day, unless your health-care team has told you to drink more or less
Add an extra cup of liquid for every watery bowel movement you have
Sip slowly on small amounts of liquid between meals
Choose drinks without caffeine or alcohol
Choose liquids with electrolytes (see below)

Liquids with electrolytes

You can buy electrolyte drinks at the store or make them at home. Sports drinks have electrolytes, but they also have a lot of sugar. Mix them with equal parts water and sports drink.

To make a homemade electrolyte replacement drink:

Six level teaspoons of sugar
Half a teaspoon of salt
One litre of tap water

Change your diet

When you have diarrhea, the following diet changes may help:

Eat many small meals and snacks instead of two or three large meals
Eat slowly, take small bites and chew your food well
Remove all skins, peels, membranes and seeds from fruits and vegetables
Limit foods that are spicy, high in fat (like deep-fried foods) or anything else that bothers your stomach
Ask to speak with a registered dietitian if diarrhea continues despite these recommendations

You can start to eat normally again when:

You do not think food is making your diarrhea worse
You have not had diarrhea for about 12 to 24 hours
You do not need to take medications to stop your diarrhea

Take care of your skin

The skin around your bum area can be painful when you have diarrhea. To avoid sores or feeling uncomfortable, use the following tips to take care of your skin:

Clean your bum with warm water and pat it dry after you pee or have a bowel movement
Over-the-counter creams and ointments with zinc oxide, such as diaper cream and stoma powder, can help protect and heal the skin
Caution: Talk to your health-care team if you are getting radiation to the pelvis (the area between the hip bones) or bum area, as creams with zinc oxide may not be safe for you to use

Soothe the skin with a sitz bath

Fill your bathtub or plastic sitz bath with warm (not hot) water
Add one to two tablespoons of baking soda or one to two teaspoons of salt to the water
Do not add bath oils or anything else to the water
Soak your bum for about 10 to 15 minutes
Have sitz baths as often as you need to stay comfortable

Key points

Stop taking laxatives when you have diarrhea
Take anti-diarrhea medications as directed by your health-care team
Watch for signs of dehydration, such as thirst, a dry mouth and tongue, and dark-yellow pee
Drink extra fluids and use electrolyte replacement drinks when you have diarrhea
Know when to contact your health-care team

Where to get more information

The Canadian Cancer Society is a trusted source of information. Visit cancer.ca or call 1-888-939-3333.

For more information on this symptom, or for guides to help manage other symptoms, visit Managing Symptoms, Side Effects & Well-Being.

If you need this information in an accessible format, contact 1-877-280-8538, TTY: 1-800-855-0511, or [email protected].

About this guide

Ontario Health’s patient guides provide Information on managing health-related symptoms (“Information”). The patient guides are for informational purposes only and are not intended to be a substitute for professional medical advice, diagnosis, treatment, or care. The information does not establish a physician-patient relationship between you and Ontario Health. Always seek the advice of a qualified health-care provider.

The patient guides may be amended, reproduced, and distributed without prior permission of Ontario Health for limited use in healthcare settings where patients may benefit from the information. Ontario Health must be cited as the source only when the patient guides are reproduced in their original form. Ontario Health is not responsible for any copyright reproduction of materials.