NCCN Guidelines for Patients
Rectal Cancer, Version 1.2017
Overview of cancer treatments
your body for a short period of time following surgery.
This type of treatment is not commonly used for
Side effects from radiation therapy differ among
people. Factors like radiation dose and length of
treatment play a role. Side effects are cumulative.
This means they build up slowly and are worse at the
end of treatment. Your doctor will check on you every
week during treatment. He or she will review skin
care, medicines, and other options to help you feel
Acute effects are those that happen during treatment
or shortly after the last session. Acute effects will
generally improve after treatment. Fatigue is an
acute effect. Skin changes and hair loss at the
treatment site are expected.
Often, people describe skin changes as like a
sunburn. Unlike a sunburn, skin changes build up
slowly during treatment. Your skin may become red,
irritated, and dry. It may also itch, darken, peel, and
sometimes crack open. Skin in regions of friction or
rubbing is prone to cracking open.
Radiation can affect the wall of your gut. Thus,
another common acute effect is watery stools
(diarrhea). You may also feel nauseated.
Radiation may irritate your urine system. You may
have discomfort when peeing. You may have trouble
starting and maintaining a urine stream.
Late effects are those that happen after treatment.
Some do not go away. Rarely, chronic diarrhea or
bloody stools occur. Strong bowel urges or loss of
bowel control also uncommonly occur. There is a
rare risk for weakening of pelvic bones. At worst, they
may fracture. Rarely, scar tissue blocks the gut.
You may have sexual problems. Men may not be
able to get normal erections. Women’s vaginal canal
may not stretch as normal causing dryness and pain
during sex. Vaginal dilators from your doctor may
prevent or reduce this late effect. Women’s sex drive
may also drop due to damage to ovaries.
You may not be able to have children naturally after
treatment. The cells in men that make sperm may
not work well. Likewise, eggs in women may be
Tell your doctor if you want to talk with a fertility
specialist before treatment. A fertility specialist is an
expert in helping people have babies. You and the
fertility specialist can discuss your options for how to
have a baby after treatment.
Not all the side effects of radiation have been listed
here. Please ask your treatment team for a complete
list of side effects. If a side effect bothers you, tell
your treatment team. There may be ways to help you