['Spina bifida occulta (SBO) is a common developmental variant. The aim of this study was to re-examine the possible association between SBO and constipation in children.', 'A total of 113 children with constipation underwent plain abdominal radiography, anorectal manometry, neurophysiologic study, electromyography testing, and colonic transit study. Eighty-six were diagnosed with functional constipation (FC) and 27 were diagnosed with nonretentive fecal incontinence (NRFI). The incidence of SBO in these children was compared with 226 sex- and age-matched controls. Twenty-four SBO children with either FC or NRFI also underwent individualized biofeedback training and electric stimulation therapy based on the investigation results.', 'The incidence of SBO in the FC and NRFI groups was 47.7% and 77.8%, respectively. Statistically, this is significantly higher than that of the control group (chi-square, 23.9%; P < .05). Compared with the FC or NRFI children without SBO, the FC and NRFI children with SBO had decreased vector volumes and electromyography amplitudes, increased rectal sensory thresholds, and prolonged latency of pudendo-anal reflex. All 24 children who underwent individualized biofeedback training and electrical stimulation treatment had sustained symptomatic improvement with less straining, fewer incomplete bowel movements, and less abdominal pain. The recovery rate was 79.2% (19 of 24).'] Is constipation associated with spina bifida occulta in children?