Introduction

Urolithiasis is a fairly common disease in adults with an estimated prevalence of 3% to 5%. In economically developed countries, urolithiasis has been regarded as an uncommon condition in children. The estimated incidence in the United States from the 1950s to the 1970s is approximately 1% to 2% that of adults. More recent studies from the United States suggest an increase in the incidence and prevalence, with one study demonstrating a nearly 5-fold increase in the incidence in the last decade. Reports regarding gender predisposition have varied, with some studies suggesting equal prevalence and others indicating a greater risk among boys. Race and geography seem to play a vital role in the prevalence and cause of pediatric stone disease. In certain regions, such as Southeast Asia, the Middle East, India, and Pakistan, calculi are endemic. Calculi are particularly uncommon in children of African descent. The endemic calculi observed in developing nations are often confined to the bladder and comprise predominantly ammonium acid, urate, and uric acid, and seem to correlate with a decreased availability of dietary phosphates. In the United States, urolithiasis seems to be more common in Caucasian children from the Southeastern region. Over the last 3 decades the cause of childhood urolithiasis in the United Kingdom has shifted from predominantly infectious to metabolic in nature. Most calculi in the United States are found in the kidneys or ureters, comprise either calcium oxalate or calcium phosphate, and often associated with a metabolic abnormality.