National Cancer Institute

Managing Radiation Therapy Side Effects

What to do when you have loose stools 

(diarrhea)

What is diarrhea?

Do you have bowel movements more 

often than normal? Are they soft, loose, 

or watery? Then you may have diarrhea. n Call your doctor or nurse if you 

have diarrhea, stomach pain, 

or feel dizzy. 

n Ask about foods and medicine 

that can help.

Take these steps to feel better:

Drink more liquids each day.

Drinking will help you feel better. 

Although it won’t stop the diarrhea, 

it will help prevent dehydration (loss 

of too much water from the body). n Drink lots of clear liquids, such as 

water, ginger ale, and clear soup.

n Most people who have diarrhea need 

to drink 8 to 12 cups of liquid each 

day. Ask your doctor or nurse how 

much you should drink.

Eat small meals that are easy on 

your stomach. n Eat small meals throughout the day, 

instead of 3 large meals.

n Your doctor or nurse may suggest the 

BRAT foods. BRAT stands for: Bananas Rice Applesauce Toast

Limit or avoid foods and drinks that 

can make your diarrhea worse. n Don’t eat spicy, greasy, or fried foods. n Don’t have milk or dairy products 

such as cheese or ice cream. Check 

food labels to see if milk products 

are listed. 

n Don’t have drinks with caffeine 

or alcohol.

n You may need to avoid or have less 

raw fruit, vegetables, and whole 

wheat breads and cereals. 

n Ask your doctor or nurse what foods 

you may need to avoid.

“Diarrhea kept me from going out and 

doing things. My nurse told me how 

important it was to drink more liquids. 

Drinking more water and avoiding certain 

foods helped me feel a lot better.”

u.s. Department 

of health and

human services National Institutes

of Health
How can we help?

National Cancer Institute’s Cancer Information Service

Phone: 1-800-422-6237 (1-800-4-CANCER)

Web: www.cancer.gov

Online Chat: www.cancer.gov/livehelp

NCI has a series of 9 Radiation Therapy Side Effects Fact Sheets at:

www.cancer.gov/radiation-side-effects

Managing Radiation Therapy Side Effects: When you have loose stools (diarrhea)

Taking care of your bottom 

(rectal area):

n Use a baby wipe that is alcohol free 

and unscented.

n It may help to sit in a shallow, warm bath 

(sitz bath).

n Let your doctor or nurse know if your rectal 

area is sore or bleeds.

Questions to ask your doctor or nurse:

1. What problems should I call you about?

2. How much liquid should I drink each day?

3. What foods and drinks should I limit or avoid?

4. What are oral rehydration solution drinks? 

Where can I find them?

5. What is a sitz bath? Should I take these?

6. What products can I use if my bottom is sore 

or bleeds? What should I not use?

NIH Publication No. 11-6102

Revised December 2010

These foods and drinks may be easy on your stomach until you feel better:

Soups (clear liquids) Drinks (clear liquids) Meals and snacks Fruits and other foods

•	Clear broth, such as

chicken, vegetable, 

and beef

•	Clear soda, such as

ginger ale

•	Cranberry or

grape juice

•	Oral rehydration

solution drinks, 

such as Pedialyte®

•	Tea

•	Water

•	Chicken—broiled

or baked, without 

the skin

•	Crackers

•	Cream of wheat or

rice cereal

•	Noodles

•	Oatmeal

•	Potatoes—boiled,

without the skin

•	Pretzels

•	White rice

•	White toast

•	Applesauce

•	Bananas

•	Canned fruit, such as

peaches and pears

•	Gelatin (such as

Jell-O®)

Most canned or 

cooked fruits and 

vegetables without 

seeds or skins 

are easy on 

your stomach.