Comparison of uroflow parameters in children with pure constipation versus constipation plus lower urinary tract symptoms*

Functional constipation as a risk factor for pyelonephritis and recurrent urinary tract infection in children

AIM

Acute pyelonephritis is one of the most common bacterial infections in childhood. This potentially serious condition can lead to renal scarring, loss of kidney function and hypertension. The aim of this study was to identify risk factors associated with pyelonephritis in children without kidney or urinary tract abnormalities.

METHODS

Medical records of children aged 4-18 diagnosed with 1st time pyelonephritis from 2016 to 2021 were retrospectively analysed. Children with abnormal kidney ultrasound were excluded. In addition to demographic data, information on bladder and bowel function was extracted together with habits of fluid intake.

RESULTS

A total of 105 patients were diagnosed with 1st time pyelonephritis. Of these, 47% were diagnosed with constipation according to the Rome IV criteria within a mean follow-up period of 167 days after their pyelonephritis, which is markedly higher than the estimated prevalence of constipation in the background population. Constipation was positively associated with recurrent urinary tract infection (p = 0.01).

CONCLUSION

Constipation is associated with pyelonephritis and recurrent urinary tract infection in children (primarily girls) 4-18 years of age without evident kidney or urinary tract abnormalities. We recommend systematic evaluation of bowel and bladder function after 1st time pyelonephritis in all children >4 years.

Influence of constipation on enuresis

INTRODUCTION

Constipation has classically been considered as a risk factor of enuresis, although there are increasingly more publications that report a similar prevalence of constipation in both enuretics and non-enuretics.

OBJECTIVE

To determine the influence of constipation in monosymptomatic and non-monosymptomatic enuresis, and to find out the prevalence of the three disorders, as well as the lower urinary tract dysfunction and bladder-bowel dysfunction in the population.

MATERIAL AND METHOD

A cross-sectional observational prevalence study on a representative population sample of 5-9 year-old school boys and girls of Galicia, Spain. A questionnaire was completed in the schools on urinary and bowel habits, which included questions from the Paediatric Lower Urinary Tract Scoring System (PLUTSS) diagnostic questionnaire and grading of the lower urinary tract dysfunctions. The enuresis was diagnosed using the International Children's Continence Society (ICSS), and if it was also associated with diurnal symptoms, it was also classified as non-monosymptomatic enuresis. The constipation was evaluated using the Rome III criteria and the adapted Bristol stool scale.

RESULTS

A total of 772 questionnaires were included in the study. The prevalence of constipation was 20% and that of enuresis was 9.1% (62.9% monosymptomatic enuresis and 37.1% non-monosymptomatic), with the prevalence of bladder-bowel dysfunction being 5.2%. It was observed that constipation had no influence on the presence of monosymptomatic enuresis, but it did have an influence on non-monosymptomatic enuresis and lower urinary tract dysfunctions, where it was a significant risk factor.

CONCLUSIONS

The differential diagnosis between monosymptomatic and non-monosymptomatic enuresis is essential in the initial evaluation of the patient with enuresis, since the therapeutic management and the characteristics of both disorders are different, with constipation only being a risk factor in cases of non-monosymptomatic enuresis.

Genitourinary and gastrointestinal co-morbidities in children: The role of neural circuits in regulation of visceral function

OBJECTIVE

Pediatric lower urinary tract dysfunction (LUTD) is a common problem in childhood. Lower urinary tract symptoms in children include overactive bladder, voiding postponement, stress incontinence, giggle incontinence, and dysfunctional voiding. Gastrointestinal co-morbidities, including constipation or fecal incontinence, are commonly associated with lower urinary tract (LUT) symptoms in children, often reaching 22-34%. This review summarized the potential mechanisms underlying functional lower urinary and gastrointestinal co-morbidities in children. It also covered the current understanding of clinical pathophysiology in the pediatric population, anatomy and embryological development of the pelvic organs, role of developing neural circuits in regulation of functional co-morbidities, and relevant translational animal models.

MATERIALS AND METHODS

This was a non-systematic review of the published literature, which summarized the available clinical and translational studies on functional urologic and gastrointestinal co-morbidities in children, as well as neural mechanisms underlying pelvic organ 'cross-talk' and 'cross-sensitization'.

RESULTS

Co-morbidity of pediatric lower urinary and gastrointestinal dysfunctions could be explained by multiple factors, including a shared developmental origin, close anatomical proximity, and pelvic organ 'cross-talk'. Daily physiological activity and viscero-visceral reflexes between the lower gastrointestinal and urinary tracts are controlled by both autonomic and central nervous systems, suggesting the dominant modulatory role of the neural pathways. Recent studies have provided evidence that altered sensation in the bladder and dysfunctional voiding can be triggered by pathological changes in neighboring pelvic organs due to a phenomenon known as pelvic organ 'cross-sensitization'. Cross-sensitization between pelvic organs is thought to be mainly coordinated by convergent neurons that receive dual afferent inputs from discrete pelvic organs. Investigation of functional changes in nerve fibers and neurons sets certain limits in conducting appropriate research in humans, making the use of animal models necessary to uncover the underlying mechanisms and for the development of novel therapeutic approaches for long-term symptomatic treatment of LUTD in the pediatric population.

CONCLUSION

Pediatric LUTD is often complicated by gastrointestinal co-morbidities; however, the mechanisms linking bladder and bowel dysfunctions are not well understood. Clinical studies have suggested that therapeutic modulation of one system may improve the other system's function. To better manage children with LUTD, the interplay between the two systems, and how co-morbid GI and voiding dysfunctions can be more specifically targeted in pediatric clinics need to be understood.