A bladder calculus is a mass of mineral deposits that is either formed in the urinary bladder or descends from the pelvis of the kidneys. Primary bladder calculi are rarely encountered in the Western world and are usually secondary to urinary stasis following an obstruction.
Bladder calculus develops in cases of urinary stasis, chronic infection or as a result of a foreign body. Patient history can provide data about possible causes of calculi formation contributing to stasis, for example, outlet obstruction due to prostate hyperplasia or malignancies in the prostate gland. Patients with neuronal damage e.g. in stroke or spinal cord injury, or diabetes mellitus are at risk of developing neurogenic calculi, hence inquiry about the latter is useful. Indwelling urethral catheterization, recurrent urinary tract infections can also be a cause of bladder calculi, for that reason, history of previous inpatient care, surgeries and previous infections should be obtained  . Descending renal stones can also result in bladder calculi. In such cases a patient may have had previous renal colics or renal stones .
On examination, a palpable mass in the suprapubic region can be found.
Symptoms may range in intensity i.e. they can be completely absent or patient will complain of suprapubic pain, dysuria, frequency, urgency, hesitancy and a small stream. Additionally, symptoms of gross hematuria, nocturia, pollakiuria, dysuria, or abrupt cessation of voiding can be present  . Small children may encounter episodes of priapism, as well as occasional enuresis .
In patients with a bladder calculus, urinalysis is essential to identify the presence of red blood cells (RBC), pyuria, levels of nitrite and urine pH, which is acidic e.g. in the case, of uric acid calculi. Microscopy may provide clues about stone composition that correlates with crystals found in the urine .
The first examination is usually an imaging study i.e. plain radiography of kidneys, ureters, and bladder (KUB) that helps identify radiopaque calculi. These stones may be coated with calcium crystals that contribute to their detection on x-ray. If no stones are detected, but clinical presentation suggests calculi, then an ultrasonography of the bladder is advised to reveal these mineral deposits .
Ultrasonography is a convenient method, for it is useful in identifying calculi that would have been missed on plain radiology. Ultrasonography exposes the stones as hyperechoic bodies with posterior shadowing and renders detection of both radiopaque and radiolucent stones  . It is also useful in differentiating stones from tumors of the bladder, as stones reposition during movement. Tumors, on the other hand, are fixed to the tissues and appear non-motile. Although, these findings are insufficient for diagnosis or exclusion of a malignant tumor .
Intravenous pyelogram (IVP) or cystography may reveal disrupted flow of contrast due to calculi .
Cystoscopy is the diagnostic method of choice and is usually performed after imaging studies. Cystoscopy confirms bladder stones including their location, quantity, and size. Furthermore, it is useful for identifying structures contributing to urinary stasis, like urethra, prostate, anatomical orifices of ureters in the bladder or bladder mucosa and its anatomical characteristics .