Bladder stone is a special group of urinary stone that is formed either primarily in the bladder or was formed in the kidney but was arrested at the bladder on its way out. Here in the bladder it continues to grow.

The cause for bladder stones and its treatment are different from kidney stones.

What causes bladder stones?

Bladder stones that are formed primarily in the bladder is caused by:

1. Bladder outlet obstruction.
   The most common cause of this is prostate enlargement (BPH). You can read more about this condition in the Prostate Clinic section. The stagnant residual urine provides a constant pool of chemicals for stone to cystalise in the bladder, giving rise to bladder stones. It may also be triggered by infection of the urine.
   
   
2. Urine infection
   Bacteria in the urine can break down certain chemicals in the urine to form stones. Infection with parasites such as schistosomiasis can also lead to stone formation.
   
   
3. Neurogenic bladder
   The incomplete emptying of the bladder leading to urine stagnation will lead to stone formation as in bladder outlet obstruction.
   
   
4. Bladder diverticulum
   This is a structural weakness of the bladder wall forming a blind pouch. This creates a collecting area that does not drain properly when passing urine leading to urine stagnation and stone formation.

What are the symptoms of a bladder stone?

The affected person may walk around with a bladder stone for years without noticing.

When the bladder stone rubs against the mucosa (soft lining) of the bladder, blood may appear in the urine (hematuria). Typically the blood will appear towards the end of urination.

Other symptoms includes:

1. Frequent need to pass urine
2. Interrupted urine flow
3. Urgent urination
4. Difficult and painful urination (dysuria)
5. Easier to urinate in certain position
6. Pain over the lower abdomen. Especially when walking
7. Dark colored urine
8. Urinary tract infection
9. Fever 

How is a bladder stone detected?

A bladder stone can be detected with an X-ray or ultrasound of the bladder.

This can be visualized with a cystoscope, which is a telescope inserted into the bladder through the natural urinary tract. Instruments can be inserted through this telescope to crush smaller bladder stones.

Removing Bladder stone

This procedure is usually performed under general or regional anesthesia.

A telescope is passed into the bladder and the bladder stone visualized. A crushing instrument with jaws known as a lithotrite is then inserted. In the sequence of pictures below, the surgeon catches the stone in the jaws of the instrument and crushes it. This is known as litholapaxy. The fragments are then washed out of the bladder.

For bigger stones, the stone can be fragmented with an ultrasonic probe. This is known as ultrasonic lithotripsy. The picture below shows stone fragments after ultrasonic lithotripsy. The fragments are then removed.

The patent can be discharged after a few hours of observation without any overnight hospital stay.