This study shows that there is significant improvement in bladder function in children with FC who undergo a BMP. This is evidenced by the significant improvement in VSS. For challenging patients with BBD and FC, a BMP is a reasonable treatment strategy to treat lower urinary tract symptoms.
The VSS is a 14-item questionnaire that assesses urinary continence and also the severity of symptoms associated with BBD and fecal incontinence [7]. A score of 11 or higher is indicative of nonneurogenic lower urinary tract dysfunction/dysfunctional elimination syndrome, with a sensitivity of 80% and specificity of 91%. The median pre-BMP VSS score in our cohort was 14, which would characterize the patients as having DES. After the BMP, the median VSS decreased to a median of 10, thereby showing enough improvement in patient symptoms to the degree that they no longer were considered dysfunctional eliminators. This was true in patients who performed only one BMP and those who underwent multiple BMP. Both of these groups ultimately scored a median of less than 11 which suggests that improvement and resolution of BBD is possible with BMP alone.
It has been shown previously in patients with anorectal malformation who have underwent a BMP that the VSS improves as fecal continence in the population improves [15]. Children with anorectal malformation have known associated urologic abnormalities and commonly have difficulty with urinary and bowel elimination. Additionally, children with these malformations often have multiple surgical procedures that may impact bowel and bladder function. In contrast, children with FC have normal urologic and colorectal anatomy and rarely, if ever, has surgery been performed. Our finding that BMP alone significantly improves VSS in these patients reinforces the well-accepted concept that fecal retention can cause urinary symptoms, even in children with no underlying neurologic or anatomic abnormality. Our study is the first to our knowledge that shows that BMP alone can improve the VSS in children with FC. Additionally, we saw improvement in the BCS and CCCS scores as well. The BCS is a scoring measure used to assess social continence in children who have underwent repair of an anorectal malformation [17]. The patients in this cohort had FC, not an anorectal malformation, but both populations have been known to have concomitant urinary dysfunction [6, 11, 15]. The CCCS, while validated for adults, is a scoring system that assesses the severity of symptoms of constipation [16]. Improvement in both of these scores, along with the VSS, supports the interrelatedness of constipation and urinary dysfunction.
It has been reported that nearly 50% of patients seen in pediatric urology clinics have issues with BBD [1, 19]. Bowel and bladder dysfunction can cause negative physical and psychosocial effects on children and their families [4]. Given the economic and psychosocial effects of BBD, it is important to identify adequate treatments that may prevent additional morbidity for patients suffering from it. Additionally, urologic testing commonly requires catheterization, radiation exposure, and sometimes sedation. The objective improvement in VSS seen in our study suggests that if a formal BMP is initiated as a first line treatment for dysfunctional elimination, symptoms may improve enough to eliminate the need for such testing or any additional intervention aimed at bladder control, such as medication.
This study does have several limitations. First, the VSS itself demonstrates 80% sensitivity and 91% specificity for dysfunctional elimination syndrome/BBD, meaning we may not be identifying all patients with BBD [7]. Second, we did not assess the association of these scores with stool and urinary continence. The BCS and CCCS were not validated for our population of pediatric patients with FC and BBD. The median time at which the VSS was measured post-BMP was only 92 days and therefore we are unable to describe the longevity of the impact of a BMP on BBD. Lastly, this is a single-institution study performed at a specialized, high-volume center, so results may not be generalizable.
We conclude that in children with function constipation and concomitant bladder dysfunction, a bowel management program significantly improves urinary symptoms. Thus, in this patient population, a bowel management program should be undertaken prior to any other measures to control bladder dysfunction.