To compare the frequency of spina bifida occulta (SBO) detected in patients with nocturnal enuresis (NE) and to investigate its clinical significance.

Patients aged 6 to 15 years who were admitted to the urology clinic with NE were included in this prospective study. The control group consisted of patients who were admitted with a complaint of abdominal or lateral pain. The patients who had lower urinary tract symptoms (LUTS) were classified as nonmonosymptomatic NE (NMNE). Those with monosymptomatic NE were treated with desmopressine. In patients with NMNE, treatment with oxybutynin was added if an overactive bladder or uninhibited contraction was detected by urodynamics.

A total of 184 NE and 180 control patients were included in the study. SBO was detected in 71 (19.5%) patients and LUTS in 100 (27.4%). When the groups with and without NE were compared, the number of patients with SBO (26% vs 17%, P = .044) and those with LUTS (36% vs 17.5%, P < .001) were significantly higher in the NE group. The overall rate of dryness (67.4% vs 83.6%, P = .024) and response to LUTS treatment (65% vs 97%, P < .01) were significantly lower in those with SBO than in those without SBO.

SBO is more common in NE patients than in non-NE patients. Response to NE treatment is lower in SBO patients with severe LUTS; for this population, advanced treatment options may be considered earlier.