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Radiation to the pelvis

There is always the potential for some side effects to occur when radiation therapy is given to the pelvic area. Radiation therapy to the pelvis can irritate the large and small intestines and result in gastrointestinal (GI) problems. Other structures in the pelvis, such as the bladder and reproductive organs, can also be affected by radiation. Side effects usually begin 2–3 weeks after treatment starts. Most side effects go away once treatment is over, but a few may continue or occur long after radiation treatment.

Bowel problems

Radiation to the pelvis can cause a variety of bowel problems, including:

  • irritation of the large or small intestines during or after radiation therapy to the pelvis, causing diarrhea or radiation enteritis
  • pain or itching during bowel movements, if the rectum is treated with radiation
  • narrowing (stricture) of the rectum or rectal spasms
  • partial loss of bowel control
  • inflammation of the rectum or anus, causing bloody stools and a frequent urge to have a bowel movement
  • painful and ineffective straining when trying to have a bowel movement (tenesmus)
  • rectal bleeding
  • flare-up of hemorrhoids, especially if the person had them before treatment

Bowel habits usually return to normal after treatment is finished. However, some of these problems, such as strictures, can occur several months or years after radiation therapy.

The radiation therapy team can suggest ways to help manage diarrhea, itching and hemorrhoids. Treatment options for severe rectal problems may include:

  • anti-inflammatory drugs, corticosteroid drugs or medicines to treat spasms
  • dilation or widening of rectal strictures
  • surgery, if the problem is severe enough

Long-term effects may include scarring of the rectal tissue (called rectal fibrosis), rectal bleeding, bowel perforation, bowel adhesions, atrophy or obstruction.

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Excessive gas

Excessive gas (flatus) can occur when radiation causes irritation and inflammation in the intestinal (bowel) wall. Gas often begins 2–3 weeks into radiation therapy and can become uncomfortable because it causes the intestinal wall to stretch. These symptoms are usually temporary and will go away once treatment is finished and the inflammation decreases.

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Bladder problems

Radiation therapy can irritate the bladder and make it inflamed (called cystitis). Symptoms of bladder irritation or inflammation include:

  • bladder spasms
  • burning or pain during urination
  • intense need to urinate (urgency)
  • need to urinate often (frequency)
  • blood in the urine (hematuria)
  • bladder infection
  • urinary incontinence (loss of bladder control)

Symptoms usually occur 3–5 weeks after radiation therapy starts. Most symptoms gradually go away 2–8 weeks after radiation therapy is completed. Some symptoms, such as cystitis or incontinence, may continue or develop after treatment is over.

Drinking plenty of fluids to ensure a regular flow of urine and emptying the bladder frequently may help people manage bladder problems. Report burning, pain and frequent urination to the radiation therapy team. These can also be symptoms of infection.

The healthcare team my recommend medicines to help treat some of the symptoms associated with bladder problems.

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Reproduction problems

The reproductive organs may be affected by radiation therapy, depending on the amount of tissue treated and the dose of radiation therapy given. The radiation therapy team will often try to shield the reproductive organs from radiation, unless they contain cancer. Some radiation scatter (radiation energy that is given off outside the treatment area) may be unavoidable and the testicles or ovaries may be exposed to small amounts of radiation.

  • Some people may lose interest in sex. This may be related to lower ovarian or testicular function.
  • Women may have vaginal symptoms or their ovarian function can be affected, which may cause menopausal symptoms or fertility problems.
    • Girls may have delayed development of secondary sex characteristics.
  • Men may have fertility problems or erectile dysfunction (impotence).
    • Boys may have delayed development of secondary sex characteristics.

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gastrointestinal (GI)

Referring to or having to do with the digestive organs.

The gastrointestinal (GI) tract, or digestive tract, includes the mouth, pharynx (throat), esophagus, stomach, small intestine and large intestine.


The body’s protective response to injury or infection that includes redness, swelling, pain and warmth of the affected area.


Any steroid hormone that acts as an anti-inflammatory by reducing swelling and lowering the body’s immune response (the immune system’s reaction to the presence of foreign substances).

Corticosteroids are made by the adrenal gland. They can also be produced in the lab.


Thinning or wasting away of a cell, tissue or body part.


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