Objective: To explore the pathophysiological significance of spina bifida occulta (SBO) in non-retentive fecal incontinence (NRFI) in children.
Methods: Twenty-seven children with NRFI diagnosed according to the Rome III criteria, 21 with SBO, aged (7.9 +/- 2.4) years, and 6 without SBO, aged (7.5 +/- 1.9) years, and 226 normal controls, aged (8.4 +/- 2.7) years, underwent plain X-ray photography, neurophysiological study, colonic transit test, electromyography (EMG), and anorectal manometry. The resting vector volume, squeezing vector volume, resting EMG amplitude, and squeezing EMG amplitude, which predominantly reflect internal and external anal sphincter function, were recorded.
Results: The prevalence rate of SBO in the children with NRFI was 78%, significantly higher than that of the normal controls (24%). The resting vector volume, squeezing vector volume, resting EMG amplitude, and squeezing EMG amplitude, of the children with NRFI were all significantly lower than those of the normal controls; however, there were no significant differences in these indexes between the NRFI children with and without SBO. The total colonic transit time of the NRFI children with SBO was (41 +/- 17) h, significantly longer than those of the children without SBO and normal controls (24 +/- 5) h and (29 +/- 8) h, both P < 0.05]. Neurophysiologic test showed that the latency of pudendi-anal reflex of the NRFI children with SBO was (52 +/- 20) ms, significant longer than those of the NRFI children without SBO and normal controls [(29 +/- 9) ms and (23 +/- 7) ms respectively, both P < 0.05].
Conclusion: SBO is a major cause of NRFI. Treatment should be focused on recovery of the functions of nervous system.