The age of pediatric urolithiasis patients at diagnosis ranged from 8 months to 15 years old with an average of 7.86±4 years (Mean±SD). 81 were boys and 23 girls, while the sex ratio was 3.5:1 boys to girls.
Stones were located in the upper urinary tract among 62.5% of cases (kidney: 47.1%, ureter: 15.4%), and were mostly found in children over 5 years old, and in the lower tract in 37.5% cases (bladder: 30.8%; urethra: 6.7%) (Fig. 1).
The stone sizes were also determined by echography and scanner varied between 4 and 40mm (Fig. 2).
At the time of diagnosis, 19 patients (18.3%) had positive urine cultures; E. coli was the most commonly encountered microorganism. It represents 47.4% of species. P. mirabilis, P. aeruginosa and Enterobacter genus represented 10.5%.
While considered to be rare in children, several studies suggest that urolithiasis is becoming more common in pediatric patients  and it remains a common health problem in some parts of the world, such as Turkey , Pakistan, and Afghanistan [6,7].
The prevalence of urolithiasis varies according to geographic areas and risk factors .
More recent reports suggest that urinary calculi are being recognized with an increasing frequency [9,10].
In Morocco, unlike in adult patients, epidemiological studies in children are fewer [11,12].
In our data, a prevalence of 0.83% of childhood urolithiasis was calculated, which is less than the prevalence in the United States which was estimated to be 5.2% , whereas prevalence in a Turkish population under the age of 14 was 17% . Annual incidence has been estimated to be 1.8 per 100,000 children per year in Kuwait .
A male predominance was confirmed with a sex ratio of 3.5. This ratio is comparable to that given by Oussama et al.  in Middle Atlas and is higher than the one observed in France .
In our study 62.5% of stones were located in the upper urinary tract. This result was consistent with the results of recent studies in developed countries [17,18].
According to the literature, the presenting signs and symptoms of pediatric stone disease are different from those in adults . They have varied presentations including nonspecific pain located in the abdomen, flank, or VE-822 which may be confused with colic pain. In this study, those symptoms were present in 38.75% of patients. This value is higher than that of Turkish study ; and these symptoms were most commonly presented in Children having more than 5 years old [21,22].
Macroscopic or microscopic hematuria can occur in up to 90% of children with urolithiasis . In our series, Revertant represented 28.75% of symptoms.
Urethral and urethral stones can cause obstruction that leads to pain [24,25], we showed that urinary obstruction was present in 17.5% of patients.
A total of 5% of children had associated anatomical abnormalities of urinary tract, whereas in a Turkish study  they were present in 8.9% of children.
Unlike the developed countries where traditional surgery was replaced several years ago with non-invasive techniques, our study revealed that the open surgery remains the most frequently used treatment of urolithiasis in children. This is due to the inadequacy of the ESWL in Hassan II University-Hospital center to the size of the children. The same problems are mentioned by other studies carried out in Morocco [12,26].
Ethical committee approval
Conflict of interest
Stone disease is endemic in Pakistan and constitutes 60% of the urological workload [1,2]. Extracorporeal shock wave lithotripsy (ESWL) is the treatment of choice for majority of urinary calculi, especially those smaller than 2cm in size [3,4]. However, the efficacy of ESWL as a primary treatment for lower pole stones remains controversial. The problem in lower pole stones is fragment retention rather than stone disintegration. One important factor that predicts the success of ESWL in lower pole stones is the calyceal anatomy [5–10]. The lower pole infundibular (IF) length, infundibular width (IW) and the infundibulopelvic (IP) angle on intravenous urography (IVU) have been shown to impact stone clearance [6,8,10–13]. Among these radiological parameters, the definition of IP angle has varied among the studies and remains problematic and controversial . Measurement of the angle by Elbahnasy depended on fixed points and hence provided more consistent landmarks . He used ureteropelvic axis rather than pelvic axis and vertical axis of the lower infundibulum. The use of ureteropelvic axis rather than pelvic axis resulted in a more acute angle, thus a lower cut off point was advisable. Different investigators used different cut-off values of the IP angle resulting in conflicting results [4,8–14]. However, the mean angle in many studies was around 40–50 degrees rather than 90 degrees found in the original resin endocast study of 146 cadaveric kidneys [4,5]. Therefore, we set a cut-off point at 45 degrees to see if this cut-off value is useful.