Side effects from radiation therapy to the stomach and abdomen

If you are getting radiation to your stomach or some part of the abdomen (belly), you may have side effects such as:

  • Nausea
  • Vomiting
  • Belly cramps
  • Diarrhea

You can get medicines to help relieve these problems. Check with your cancer care team about any home remedies or over-the-counter drugs you’re thinking about using.

Managing nausea

Some people say they feel queasy for a few hours right after radiation therapy. If you have this problem, try not eating for a couple of hours before and after your treatment. You may handle the treatment better on an empty stomach. If the problem persists, ask your cancer care team about medicines to prevent and treat nausea. Be sure to take the medicine as prescribed.

If you notice nausea before your treatment, try eating a bland snack, like toast or crackers, and try to relax as much as possible. Here are some tips to help an upset stomach:

  • Stick to any special diet your cancer care team gives you.
  • Eat small meals.
  • Eat often and try to eat and drink slowly.
  • Avoid foods that are fried, spicy, sweet, or high in fat.
  • Drink cool liquids between meals.
  • Eat foods that don’t have strong smells and can be served cool or at room temperature.
  • For a severe upset stomach, try a clear liquid diet (broths and juices) or bland foods that are easy to digest, such as dry toast and gelatin.
  • Learn deep-breathing and relaxation techniques, and try them when you feel nauseated.

Please call us or visit our website for more detailed information on how to manage nausea and vomiting.

How to handle diarrhea

Diarrhea most often begins a few weeks after starting radiation therapy. Your cancer care team may prescribe medicines or give you special instructions to help with the problem. Diet changes may also be recommended, such as:

  • Try a clear liquid diet (water, weak tea, apple juice, peach nectar, clear broth, popsicles, and plain gelatin) as soon as diarrhea starts or when you feel like it’s going to start.
  • Don’t eat foods that are high in fiber or can cause gas or cramps, such as raw fruits and vegetables, beans, cabbage, whole-grain breads and cereals, sweets, and spicy foods.
  • Eat frequent, small meals.
  • Do not drink milk or eat milk products if they irritate your bowels.
  • When the diarrhea starts to improve, try eating small amounts of low-fiber foods, such as rice, bananas, applesauce, yogurt, mashed potatoes, low-fat cottage cheese, and dry toast.
  • Be sure you take in enough potassium (it can be found in bananas, potatoes, beans, peaches, and many other foods). This is an important mineral you may lose through diarrhea.

Diet planning is an important part of radiation treatment of the stomach and abdomen. Keep in mind these problems should get better when treatment is over. In the meantime, try to pack the highest possible food value into even small meals so you get enough protein, calories, vitamins, and minerals.

The American Cancer Society medical and editorial content team
Our team is made up of doctors and master’s-prepared nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.

Last Medical Review: June 30, 2015 Last Revised: June 30, 2015

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