Hydrodistension (Controlled Hydrodilatation)

What is it?

Hydrodistension (or hydrodilatation) is usually performed as during a cystoscopy – a “telescopic” inspection of the bladder. It is a technique to “stretch” the bladder muscle that can be used both as a diagnostic aid and a therapy for certain conditions of the bladder.

It is often done to diagnose painful bladder syndrome/interstitial cystitis. It can sometimes provide relieve bladder symptoms associated with painful bladder syndrome/interstitial cystitis or the overactive bladder.

What happens during the procedure?

You will usually have a “light” general anaesthetic, though occasionally a spinal anaesthetic is preferred. The anaesthetist will discuss this with you prior to the procedure.

You will usually be given antibiotics during the procedure.

A telescope is inserted through the urethra (the tube through which you pass urine) to inspect both the urethra itself and the whole lining of the bladder. The capacity of the bladder when full is measured. The bladder is slowly distended in a controlled manner then held at its maximum capacity for 10minutes.

A biopsy of the bladder may be required at the same time, to help with definitive diagnosis of your condition.

What happens after the procedure?

Sometimes there is some bleeding from the bladder after it has been stretched or a biopsy is taken. Rarely, a catheter needs to be inserted - if so, you may remain in hospital overnight. Alternatively, you may prefer to go home with the catheter attached to a “leg bag”, and have it removed in the doctor’s rooms in a day or two, at your convenience.

Usually, you should be able go home the same day, and you should be able to resume normal activities relatively quickly.

Are there any side effects?

All procedures have the potential for side effects. Although these complications are well recognised, the majority of patients do not have problems after a procedure.

There are specific risks with this surgical procedure, and these will be discussed with you before your procedure. As a guide to complement that one-on-one discussion with your surgeon, these include:

Relatively Common

  • Mild burning or bleeding on passing urine for a short period after the operation.


  • Infection of the bladder requiring antibiotics.

  • Temporary increase in bladder symptoms.

  • Requirement for a temporary indwelling catheter.


  • Delayed bleeding requiring removal of clots or further surgery.

  • Injury to the urethra causing delayed scar formation.

  • Perforation of the bladder requiring a temporary urinary catheter or return to theatre for open surgical repair.

What should I expect and do afterwards?

It is common to experience some burning when passing urine, as well as feeling the need to do so more often than normal. There may also be some light bloodstaining in the urine.

To help minimize any discomfort, you should:

  • Drink plenty of fluid – at least one glass an hour.

  • Take 2 Panadol tablets every 4 hours.

  • Take a sachet of Ural® or its equivalent every 4 hours (HINT: take it with the Panadol).