About overactive bladder syndrome

Sometimes pelvic radiotherapy can cause a long-term change called an overactive bladder. This change may start during treatment and not get better. Or it may develop months or years after treatment.

Overactive bladder symptoms include:

  • suddenly feeling you need to pass urine (pee)
  • needing to pass urine more often than usual (frequency)
  • feeling your bladder is full, even when there is not much urine in it.

Bladder retraining

Bladder retraining means learning ways to train your bladder to hold more urine. This means you do not have to pass urine as often. It is best to do bladder retraining with expert help from a specialist.

You may be asked to complete a chart to see:

  • how much you drink
  • how often you go to the toilet
  • how much urine you pass.

It is important to keep drinking plenty of fluids, at least 1 to 2 litres (2 to 3½ pints) a day, so that your bladder learns to cope. It also helps to dilute your urine. This makes it less likely to irritate your bladder.

Bladder retraining should be done over a few weeks. You start by ‘holding on’ for a few minutes when you need to pass urine. You gradually increase this by a few minutes each time. Sitting on a hard seat might help. You may find it easier to distract yourself by reading, listening to the radio, or watching television. Your specialist might have other suggestions to distract yourself, such as counting backwards.

You only do the bladder retraining in the day. By doing this, the aim is that you will eventually need to go to the toilet less often at night.

Because the bladder is a muscle, it becomes stronger with retraining exercises. After a few weeks, you should find you need to go to the toilet less often.

Possible overactive bladder treatments

If bladder retraining has not helped, your specialist might suggest other treatments.

Drugs to relax the bladder

There are drugs that can relax the bladder so it can hold more urine. These drugs can help an overactive bladder or if you leak urine (urinary incontinence). You sometimes need to take them for a while to see if they are helpful. You may need to try different ones, to find one works for you. Your doctor can tell you more.

Botulinum toxin type A (Botox)

Botox® injections can help the symptoms of an overactive bladder. They may be used if other treatments have not helped.

The injections help to relax the bladder, meaning it can store more urine. They can also help you ‘hold on’ for longer.

The treatment can be done in the outpatient department with a local anaesthetic. Sometimes, a general anaesthetic is needed. The doctor passes a thin, flexible tube with a light on the end (a cystoscope) through your urethra and into your bladder. They then inject the Botox® into the wall of your bladder.

You may find it difficult to pass urine after having this treatment. This is usually temporary. It may last for a few days or weeks. Before you have Botox® injections, a nurse will show you how to empty your bladder using a thin, plastic tube (catheter). Your doctor or nurse can tell you more about this.

The effect of Botox® usually wears off over several months. But the injections can be repeated.

Nerve stimulation

Nerve stimulation uses electrical pulses to help with bladder and bowel problems. It may be used when other treatments have not helped. Your doctor or continence adviser can explain more about it. There are 2 types of nerve stimulation.

  • Sacral nerve stimulation (SNS)

    This involves placing a wire under the skin of your lower back. This wire sends electrical pulses to your nerves that control your bladder. You need a small operation to place the wires. Before the operation, you may be given something to help you relax and feel more comfortable. Or you might have a general anaesthetic.

    To start with, you wear a small box that sends the impulses. After a few weeks, if SNS is helping, you have a second operation to fit a small permanent implant under the skin instead. This is done under a general anaesthetic.

  • Percutaneous tibial nerve stimulation (PTNS)

    This may be used if you do not want sacral nerve stimulation or Botox® treatment, or if other treatments have not worked for you. PTNS is done in an outpatient clinic.

    You sit in a chair with your leg up. A nurse places a small, thin needle through the skin near the ankle and connects this to an electrical stimulator box. A sticky pad is put on the sole of your foot and is also attached to the box. The electrical pulses are turned up until you can feel a tingling in your foot. This is then left on for 30 minutes.

    You might want to take a book or magazine to read, or have music to listen to. At the end, the needle is removed and you can go home. It can take several weeks to see if it is working for you. Most people have treatment once a week for 12 weeks. After this, you and your doctor can decide how much PTNS has helped and if more treatments are needed.

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 bladder or bowel problems.

Get a toilet card

Macmillan has a free toilet card you can use. It may help you access a toilet more quickly when you are out. You can use it in places such as shops and pubs. The card says you have a medical condition that means you need urgent access to a toilet.

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.