“Why do radiation treatments cause nausea?”

Yes when you received treatment to stomach and intestine. You should take anti nausea medication such as Zofran 8 mg about 1/2 hrs before treatment and repeat every 8 hrs

Unfortunately, whenever radiation treatments are given to abdominal organs like the stomach there is some collateral damage to nearby intestinal tissue (especially small bowel) and this often causes nausea and diarrhea. This is especially true if chemotherapy is also given. Your radiation doctor should be able to prescribe anti nausea medicines that should make the problem much more manageable.

Roger Macklis

Radiation therapy is not my area of expertise, but the radiation to your stomach is not only causing death of the cancer located there, but also damaging some of the normal tissue around it. Both processes cause inflammation of the gastric lining and thus nausea. For a more detailed explanation, I recommend speaking directly to your radiation oncologist.