14781-koppen

99 Functional defecation disorders and ADHD 4 INTRODUCTION Functional defecation disorders (FDDs) are common in childhood, comprising functional constipation (FC) and functional non-retentive fecal incontinence (FNRFI). 1 The estimated worldwide prevalence of FC in children ranges from0.7 to 29.6% 2 , while FNRFI is estimated to occur in less than 1% of children in the general population. 3 Both disorders are characterized by bothersome symptoms such as fecal incontinence. In children with FC, fecal impaction may lead to overflow fecal incontinence, while in children with FNRFI fecal incontinence occurs without signs of fecal retention. Behavioral problems are frequently reported in children with FDDs. 4–6 Likewise, gastrointestinal problems like abdominal pain and constipation are common in children with behavioral disorders, such as attention deficit hyperactivity disorder (ADHD) and autism spectrum disorders (ASD). 7–9 ADHD is defined as a persistent pattern of inattention, hyperactivity and/or impulsivity that causes impairment, with an onset before the age of 7 years. 10 The estimated prevalence of ADHD among school-aged children and adolescents is 5%. 10,11 This condition is more common in boys, reported gender ratios range from 1:3 to 1:16. 12 The etiology is multifactorial and largely unknown, but genetic, environmental and social factors are thought to play a role. 13 Reliable data on the prevalence of ADHD in children presenting with FDDs are scarce. In a retrospective cohort study using a database of the military health system in the US, children with ADHD had an increased prevalence rate of FC (4.1% vs. 1.5%) and fecal incontinence (FI) (0.9% vs. 0.15%) compared with children without ADHD. 8 More reliable prospective studies on the prevalence of ADHD in children presenting with FDDs and vice versa are needed to further clarify the possible association between these two disorders. Novel insights could contribute to optimizing diagnostic and therapeutic strategies in these children. The aim of this study was to assess 1) the prevalence of ADHD in children presenting with FDDs, and 2) the prevalence of FDDs in children with a known diagnosis of ADHD. METHODS We conducted a cross-sectional cohort study in two groups of patients between September 2014 and May 2016. The medical ethics committee of the Academic Medical Center of Amsterdam approved the study protocol (reference number W12_029 # 14.17.0029). All parents gave written informed consent.