The bladder of willful infrequent voiders: underactive or underutilized?

We previously described a lower urinary tract (LUT) condition (detrusor underutilization disorder, DUD) characterized by chronic or episodic willful deferment of voiding resulting in an expanded capacity in patients with LUT symptoms. We now further characterize these DUD patients.

We reviewed our database identifying neurologically/anatomically normal children diagnosed with DUD. Bladder capacity had to be at least >125% EBC for age to be included. LUTS, diaries and uroflow/EMG findings were analyzed.

Fifty-five children (mean age 10.5 years, range 3.7-20.2; 34F, 19M) with LUTS were diagnosed with DUD. The most common reasons for presentation included incontinence (43.6%), history of urinary tract infection (UTI) (49.1%), and urgency (30.9%). Mean percent estimated bladder capacity for age was 1.67 and following treatment mean %EBC decreased to 1.10.

DUD patients typically present with infrequent voiding, incontinence, urgency, and UTIs. They have less bowel dysfunction and frequency, and larger bladder capacities than typically found in children with overactive bladder and dysfunctional voiding. Although the symptoms associated with DUD overlap in part with those considered by the International Children's Continence Society to be typical for "underactive bladder" and "voiding postponement", DUD, we feel, is a stand-alone diagnosis.