Bladder stones

True bladder stones develop in the bladder itself and are not, as many people wrongly think, kidney stones which have migrated to the bladder. Patients often have no symptoms, but may experience symptoms as a result of concomitant urinary tract infections, or (in the case of stones with sharp edges) lower abdominal or bladder pain. Bladder stones can be quite big – the size of a goose egg is not uncommon – and usually grow over a long period. They are often found in conjunction with diverticula.

The most common reason for a bladder stone to form is being unable to completely empty the bladder, so that urine remains in the bladder after passing water. The substances dissolved in the urine crystallise out and gradually develop into bigger and bigger bladder stones. Other risk factors include recurrent or chronic urinary tract infections, long-term catheter use, and the presence of an artificial bladder created using tissue from the patient's intestine.

The most common reasons for being unable to completely empty the bladder are benign enlargement of the prostate, narrowings of the urethra caused by scarring (strictures) and neurological disorders which affect bladder emptying.

Similarly to bladder diverticula, treatment for bladder stones involves resolving the underlying cause and surgical removal of the stones. Smaller stones can be crushed using an endoscope inserted via the urethra, and the pieces removed by suction. Very large stones, by contrast, have to be removed surgically via an incision in the abdomen. The bladder then has to be sutured back together (this is referred to as 'high cystotomy').