Stratifying Treatment-Resistant Monosymptomatic Nocturnal Enuresis: Identifying the Subgroup Most Responsive to Biofeedback Therapy

Background/Objectives: A subset of children with monosymptomatic nocturnal enuresis (MNE) remains unresponsive to standard treatments such as desmopressin and alarm therapy. This study aimed to identify clinical predictors of response to biofeedback therapy in treatment-resistant MNE and to evaluate the role of bladder capacity as a stratification parameter. Methods: In this prospective study, 89 children with treatment-resistant MNE underwent six weekly sessions of biofeedback therapy involving visual pelvic floor feedback. Based on treatment outcomes, patients were classified as complete responders or partial/non-responders. Clinical characteristics including age-adjusted maximal voided volume (MVV), nocturnal polyuria, and wetting frequency were compared. Results: Patients with a complete response had significantly lower baseline MVV and age-adjusted MVV (p < 0.001). Nocturnal overactivity was more common among responders (60.6% vs. 33.9%, p = 0.017), whereas nocturnal polyuria was more frequent in non-responders (p = 0.027). Age-adjusted MVV emerged as the only independent predictor of treatment success in multivariate analysis (p = 0.045), with ROC analysis confirming its predictive value (AUC = 0.767, 95% CI: 0.667–0.866). Conclusions: These findings suggest that reduced bladder capacity and frequent night-time wetting may help identify patients who are more likely to benefit from biofeedback therapy. Bladder capacity assessment may thus serve as a useful tool in tailoring management strategies for refractory MNE.