How will radiation therapy affect my bowel function and bowel movements?

The lining of the bowel is very sensitive to radiation and may become inflamed, or swollen (a condition called enteritis) during treatments. Radiation may also cause an inflammation of the stomach (called gastritis) or an inflammation of both the stomach and the bowel (called gastroenteritis). Your treatments may cause you to have:

  • Abdominal bloating or cramps
  • Thin or loose stools
  • Watery diarrhea
  • Sense of urgency to have a bowel movement

The symptoms above may occur during the second or third week of radiation therapy. Occasionally, blood or mucus may appear in the stool.