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Extracorporeal Shock Wave Lithotripsy (ESWL)

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​What are Urinary Stones?

Chemicals in the urine may form crystals under certain conditions, which combine to form a stone. These stones may be located in the kidney or passed out spontaneously. Occasionally, larger stones may remain stuck in the kidney or ureter, causing pain, bleeding, or infection.

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What is Extracorporeal Shockwave Lithotripsy (ESWL)?

It is one method of treating urinary stones. Externally generated shockwave energy is focused on the stone, passing through the skin and soft tissues. This will fragment the stone into smaller pieces and be passed out in the urine.

What Can You Expect from the Procedure?

1. Before the Procedure

  • Inform your doctor if you are taking anti-coagulant or anti-platelets (blood thinning) medicine. You will be advised to stop these medications (including TCM) for a few days before the procedure to reduce the risks of bleeding.
  • If there is evidence of infection in the urine, it will need to be treated first.
  • One to two days prior to the procedure, take your bowel prep medication to clear your bowels. This will help us to better visualise the stone for targeting during the procedure.

2. On the Day of the Procedure

  • Do not consume any food and drinks for at least six hours before the procedure.
  • Do not drive as the medication used in the procedure will make you drowsy. We advise you to have a caregiver accompany you home after the procedure.

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3. During the Procedure

Before Extracorporeal Shockwave Lithotripsy (ESWL)

  • You will be asked to lie on the treatment table.
  • You will be connected to several devices for monitoring purposes.
  • You will receive an injection to place a small tube into a vein in the arm to allow medications to be given.
  • You will then be positioned for the procedure.

During Extracorporeal Shockwave Lithotripsy (ESWL)

  • The stone is targeted using X-ray (fluoroscopy) and/or ultrasound.
  • A number of shocks is delivered to the stone.
  • The sensation is similar to that of a rubber band tapping on the skin.
  • You may experience some discomfort or mild pain.
  • Medications (typically a painkiller) will be given to you to reduce your pain/discomfort and help you relax (moderate sedation).
  • The entire procedure will take about one hour to complete.

What are the Potential Side Effects of the Procedure?

The procedure is generally safe, but possible side effects are:


  • Blood in the urine for a short period of time after the procedure.
  • Pain in the abdomen or flank (side of a person’s body between the ribs and the hip) as the fragments pass down.


  • Stone fails to fragment, requiring other methods of treatment.
  • Future recurrence of stones.
  • Repeat session of shockwave treatment.
  • Infections may occur, hence requiring antibotics.


  • Trauma to the kidney resulting in bruising or blood clot, sometimes requiring further treatment including blood transfusion.
  • Stone fragments may get stuck in the ureter, causing obstruction, which may then require further surgical procedures.

What can You Expect After the Procedure?

  • Painkillers may be prescribed where necessary.
  • There might be skin chafing/ excoriations (irritation of the skin caused by repetitive friction) where the treatment unit was in contact with the skin.
  • You should take plenty of water to aid the passing of stone fragments and allow blood in the urine to resolve.
  • You may also be prescribed medication to help the passing of of stone fragments.
  • You will be scheduled for a follow-up appointment one month after the treatment session for review.

Inform Your Doctor Immediately if You Have:

  1. Persistent fever which is higher than 38oC and chills
  2. Excessive blood or clots in your urine or stools
  3. Difficulty or inability to urinate

The instructions in this article are non-exhaustive. In specific cases, you may receive different or additional instructions from your doctor.
You are advised to follow any specific written or oral instructions given to you by your healthcare team.
Please clarify any queries with your healthcare team when you are in doubt. 

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