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Abnormal voiding parameters in children with severe idiopathic constipation
K L Y Chung1, N S Y Chao, C S W Liu
1Division of Paediatric Surgery, Department of Surgery, Queen Elizabeth Hospital and United Christian Hospital, Hong Kong, China, kenichung@gmail.com.
Insights
Children with constipation often have abnormal voiding parameters, including issues with voided volume and post-void residual urine. A dilated rectum is linked to these abnormal voiding parameters in pediatric patients.
Area of Science:
- Pediatric Gastroenterology
- Urology
- Diagnostic Imaging
Background:
- Idiopathic constipation in children is a common condition.
- Abnormal voiding parameters may be associated with idiopathic constipation.
- Understanding these associations is crucial for effective diagnosis and treatment.
Purpose of the Study:
- To investigate voiding parameters in children diagnosed with constipation.
- To determine the prevalence of abnormal voiding parameters in this population.
- To explore the relationship between rectal diameter and voiding parameters.
Main Methods:
- Seventeen children (aged 5-17) with refractory constipation were recruited.
- Rectal diameter was measured via transpubic ultrasonography.
- Uroflowmetry and bladder ultrasonography assessed maximal flow rate, voided volume, and post-void residual urine.
Main Results:
- Over half (52.9%) of the children exhibited abnormal voiding parameters.
- Abnormalities were noted in voided volume and/or post-void residual urine.
- A dilated rectum was significantly associated with abnormal voiding parameters (p=0.015).
Conclusions:
- Abnormal voiding parameters, specifically concerning voided volume and post-void residual urine, are common in constipated children.
- Rectal dilation is a significant finding associated with these abnormal voiding parameters.
- These findings highlight the importance of evaluating voiding function in pediatric constipation.
Objective:
It is suggested that idiopathic constipation may associate with abnormal voiding parameters. In this study, we investigate the voiding parameters in children with constipation.
Methods:
Since 2010, seventeen consecutive children (12 boys, 5 girls) aged 5-17 (median = 14) with significant constipation according to Rome III criteria and who were not responding to conventional treatment (diet, laxatives & bowel training) for over 6 months were recruited. The rectal diameter (RD) was measured by transpubic ultrasonography (USG), RD >3.5 cm was considered as dilated. Each patient had uroflow measurement and bladder USG done to measure the maximal flow rate (Vmax), voided volume (VV), and post-void residual urine (PVR). Abnormal voiding parameters were defined as Vmax <12 ml/sec, VV <65 or >150% of age-adjusted expected bladder capacity (EBC) and/or PVR >20 ml.
Results:
Rectal diameter ranged from 1.7 to 8.2 cm (median = 3 cm) and was abnormally dilated in eight children. Vmax was normal in all children (median = 23.7 ml/sec). Voided volume ranged from 30 to 289% of EBC and was abnormal in six children (35.5%). Post-void residual urine varied from 0 to 85 ml and was abnormal in six (35.5 %) children. Three children (17.6 %) had both abnormal VV and PVR. On the whole, the prevalence of abnormal voiding parameters in constipated children was 52.9 %. Mean RD in normal and abnormal parameters groups was 2.8 and 4.7 cm, respectively. Rectal dilation was associated with abnormal voiding parameters (p = 0.015).
Conclusion:
Abnormal voiding parameters including voided volume and post-void residual urine are prevalent in constipated children. Dilated rectum is associated with abnormal voiding parameters.
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