Difficulty passing urine after pelvic radiotherapy

Pelvic radiotherapy can damage the nerves that control the bladder muscles. It may also narrow the tube that carries urine out of the body (the urethra).

Difficulty passing urine (retention)

Sometimes after pelvic radiotherapy you may have difficulty passing urine. This is called retention. It can happen if the nerves that control the bladder are damaged or if the tube that drains urine from the body (the urethra) is narrowed, called a urethral stricture.

These may start during treatment and not get better. Or it may develop months or years after treatment.

If you are having problems passing urine (pee) or feel that you are not emptying your bladder completely, it is important to see your doctor. If urine builds up in the bladder, it can cause infections and damage the kidneys. Your doctor or continence adviser will do tests to find out the cause so they can offer you the right treatment for your situation.

Urethral stricture

Pelvic radiotherapy can sometimes cause the urethra to become narrow. This can make it more difficult to pass urine. This narrowing is caused by scar tissue. It is called a urethral stricture.

How do you treat a urethral stricture?

Small strictures can be treated by passing tubes through the urethra to widen (dilate) it. This can be done under a general or local anaesthetic. Sometimes it may need to be repeated.

Another possible treatment for smaller strictures is an operation called a urethrotomy. This is done under a spinal anaesthetic (where you are awake but do not feel anything from the waist down) or general anaesthetic.

During a urethrotomy, the surgeon passes a tube with a light on the end (cystoscope) into the urethra. This lets them make small cuts to widen the urethra. You may have a catheter for a couple of days to let the urethra heal.

A larger stricture may need to be treated with an operation that uses tissue from another part of the body to repair the urethra. This is called a urethroplasty.

Nerve damage

Sometimes, pelvic radiotherapy can affect the nerves to the bladder. This nerve damage means the bladder muscle cannot squeeze strongly enough. This can mean the bladder does not empty completely.

Some people may need to use a catheter to empty their bladder a few times a day. This is called intermittent self-catheterisation. Your specialist can tell you more about this.

If bladder problems do not improve

If your bladder symptoms continue or do not improve after having these treatments, your specialist may talk to you about other possibilities. When symptoms are severe, an operation to remove the bladder may be an option, but this is very rare.

We have information about coping with coping with bladder or bowel problems.

Getting support

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About our information

  • References

    Below is a sample of the sources used in our pelvic radiotherapy information. If you would like more information about the sources we use, please contact us at cancerinformationteam@macmillan.org.uk

    Andreyev HJN, Muls AC, Norton C, et al. Guidance: The practical management of the gastrointestinal symptoms of pelvic radiation disease. Frontline Gastroenterology, 2015; 6, 53-72.

    Dilalla V, Chaput G, Williams T and Sultanem K. Radiotherapy side effects: integrating a survivorship clinical lens to better serve patients. Current Oncology, 2020; 27, 2, 107-112.

    The Royal College of Radiologists. Radiotherapy dose fractionation. Third edition. 2019. Available from: www.rcr.ac.uk/system/files/publication/field_publication_files/brfo193_radiotherapy_dose_fractionation_third-edition.pdf [accessed March 2021]. 


  • Reviewers

    This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert medical and health professionals and people living with cancer. It has been approved by Chief Medical Editor, Professor Tim Iveson, Consultant Medical Oncologist.

    Our cancer information has been awarded the PIF TICK. Created by the Patient Information Forum, this quality mark shows we meet PIF’s 10 criteria for trustworthy health information.