INTRODUCTION AND OBJECTIVES: Fecal incontinence (FI) is a common disorder involving both local and central factors. The enteric nervous system (ENS) is closely affiliated with the central nervous system (CNS), including centers involved with the processing of emotions (brain-gut-axis). The aim of the study is to analyze neurophysiologically the central processing of emotions in children with fecal incontinence (FI). It was hypothesized 1.) That children with FI show increased responses to emotionally charged stimuli in late visual evoked potentials; 2.) That children with constipation have more intense emotional responses than those with non-retentive FI.

METHODS: 14 children with FI and constipation, 9 with non-retentive FI, 15 healthy controls and a second control group of 13 children with ADHD were examined, including a physical exam, sonography, the CBCL, a standardized psychiatric interview (Kinder-Dips) and an intelligence test. For late visual evoked potentials, 120 neutral, 40 positive and 40 negative pictures from the International Affective Picture System (IAPS), as well as 40 pictures depicting feces were presented on a screen. An oddball paradigm was used. The stimuli were presented in randomized blocks. The p300 responses (time window of 250-450 ms) over the P3/P4 scalp electrodes were evaluated.

RESULTS: The mean age of the 23 children with FI was 9.1 years (all boys), the mean IQ 102. 83% had additional disorders, including nocturnal enuresis (44%), daytime urinary incontinence (26%), ADHD (30%), anxiety disorders (21%) and ODD (22%). Children with FI had significantly more intense responses for all stimuli over P3, but only for negative and positive stimuli over P4 compared to healthy controls. Negative pictures elicited the strongest responses. The FI and second ADHD control group did not differ. The two FI groups differed only in the later 450-650ms time window, but not for the 250-450 period.

CONCLUSIONS: Children with encopresis have a high rate of comorbid emotional and behavioral disorders. Due to the close association of the ENS and the CNS, they have increased responses in the central processing of emotions. These differences can be interpreted as a neurobiological vulnerability of the brain-gut-axis, which increases the risk for FI, as well as comorbid disorders.

Source of Funding: Saarland University