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What to Expect After Radiation Therapy for Colorectal Cancer

Because radiation affects normal cells as well as cancer cells, you may have some side effects from this treatment. Some people have few or no side effects, but if you do have them, your doctor may change the dose of your radiation. Or the doctor may stop treatment until the side effects are cleared up. So be sure you keep your doctor informed about the side effects you have.

Potential Short-Term Side Effects

These are some of the common short-term side effects:

  • Diarrhea

  • Nausea

  • Bladder irritation

  • Fatigue

  • Low blood counts, as noted from a blood test

  • Skin irritation or changes in areas that got radiation

These side effects can be unpleasant. Some of them can be controlled with medicine, and some may be helped with diet. Talk with your doctor or nurse about how to deal with them and how to know when they become serious. Usually these side effects go away a few weeks after you stop getting treatment.

Potential Long-Term Side Effects

Radiation therapy can cause some long-term side effects, depending on where the radiation was aimed. These can be more serious, so you should monitor them closely with your doctor.

  • Bowel or bladder irritation. You may feel the need to urinate or have bowel movements more often. You may also have some pain with urination or bowel movements, or see blood in the urine or stool. Be sure your doctor is aware of these problems so that they can be treated, if needed.

  • Early menopause. If you’re a woman who has not gone through menopause, you may experience menopausal symptoms. Your period may stop, and you may become infertile. Talk with your doctor about what you can do to relieve the symptoms.

  • Vaginal dryness. Women may experience vaginal dryness and narrowing. Both conditions may be permanent. You can treat them with lubricants and by using a vaginal dilator or by having sexual intercourse.

  • Decreased sperm count. Men may produce less ejaculate, and their semen may have a lower sperm count. If you’re planning on having children, you may want to visit a sperm bank before having your radiation treatments.