Patient Information

Trial Without Catheter (TWOC)


What are the intended benefits of this procedure?

We will remove your catheter and check if you can urinate normally without one.

Things to check before your appointment

Ideally, we like all our patients to have a catheter valve for 7 days prior to catheter removal. If your urine is draining into a bag worn on your leg, this needs to be changed to just a valve. If you are not sure what you have, please contact the Urology department using the number below or the number on your appointment letter. If you attend with a leg bag, we may need to reschedule your appointment.

If you have been discharged from hospital after urological surgery, there may be a reason why you have a bag so please ring on and speak to one of the Urology nurses.

Your bowels must be opening regularly.  If you are constipated this will greatly affect your ability to pass urine and you may need to ask your chemist or GP for a laxative. Your catheter will not be removed if you are constipated.

Please drink a pint of water (or non-alcoholic fluid) an hour prior to your appointment to fill up your bladder.

If you use one, please remember to bring your walking stick or frame with you. If you are unable to sit or stand without help, please call us on the number at the top of your appointment letter or the contact details at the bottom of this leaflet.

Things to bring with you

  • A spare set of lower body clothing.
  • A book, newspaper or SMART phone to pass the time (our staff can lock your phone away securely during the procedure but, at other times, you are responsible for the security of any valuable items you bring with you).
  • A snack or money to buy some lunch, if necessary.
  • Any medication that you take at lunchtime.

What are the alternatives to this procedure?

Leaving the catheter in place.

What are the most frequently occurring or serious risks of this procedure?


  • Mild burning or bleeding when passing urine for a short period afterwards.


  • Failure to empty your bladder which will result in re-catheterisation, or being taught intermittent self-catheterisation.


  • Nurse specialist being unable to re-insert a catheter, which results in the doctor needing to re-catheterise you.
  • Re-catheterisation using an introducer – a wire guide that is inserted into the urethra to guide the catheter into bladder.
  • Re-catheterisation using a supra pubic catheter – the catheter is inserted through a hole in your tummy (abdomen) and then directly into your bladder (this procedure can be done under general anaesthetic, epidural anaesthetic or local anaesthetic).

What sort of anaesthetic is used?

No anaesthetic is needed for removal of catheter so you can eat and drink as normal. The procedure is usually painless.

What does the procedure involve?

  • This procedure is done on an outpatient basis.
  • Please allow up to 6 hours for your visit.
  • You will be asked to loosen or remove your lower half of clothing to allow the nurse access to the catheter.
  • The nurse will use a syringe to withdraw the water from the small balloon that holds your catheter in place.
  • The nurse will gently removed your catheter.
  • You will be asked to sit in the waiting room and drink some more water, if necessary.
  • Once your bladder feels full, you will be asked to pass urine into a flowmeter, a toilet that measures the flow of urine.
  • We will then do a quick scan to see if there is any urine left in your bladder.

What happens after the procedure?

The nurse will keep you informed of how well you are passing your urine and will talk through any need for re-catheterisation or self-catheterisation.

You will need to pass urine twice in a normal way before going home. The nurse will let you know when you are ready to leave the hospital.

What else should I look out for?

If you develop a fever, bleeding or pain on urination please contact your GP as you may have an infection.

If you are unable to pass urine at all, please contact the nurses in the Urodynamics during office hours for help and advice. Outside these hours and at weekends, please go to your nearest Emergency Department (A&E) for them to re-insert your catheter.

Who should I contact for more information?

  • Urodynamic Nurses in the Urodynamics Unit
  • Clinical Nurse Specialist in Urology Oncology if you have a cancer condition and would like further information regarding this
  • Your Urology Consultant via their secretaries.


Urology Consultant via their secretaries 020 8934 6041
The Urodynamic Nurses - Urodynamics Unit, Corridor E of Outpatients 020 8934 3038
Clinical Nurse Specialist in Urology Oncology 020 8934 2729
Hospital Transport 0208 934 6770

Translate Please speak to a member of staff before or during your visit to the hospital if you require translation.
Accessibility Please contact the Patient Experience Team on 020 8934 3850 if you need this information in a different format.
For information accessibility please visit Kingston Hospital AccessAble www.accessable.co.uk/kingston-hospital-nhs-foundation-trust
Support services

Visit the hospital website, ask a member of staff, or ring us for details.


Switchboard 020 8546 7711

  • ‘Find Us’ page for maps, transport, registering a blue badge, disabled access
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  • Learning Disability Liaison Team 020 8934 6895
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Please speak to a member of staff before or during your visit to the hospital if you require translation support to access Patient Information. Please ring the phone number on your appointment letter, if you have one.

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Please contact the Patient Experience Team on 020 893 3850 if you need this information in a different format.
For detailed information on accessibility at Kingston Hospital visit Kingston Hospital AccessAble (https://www.accessable.co.uk/kingston-hospital-nhs-foundation-trust).

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