Systematic Review of Pediatric Functional Gastrointestinal Disorders (Rome IV Criteria)

Functional gastrointestinal disorders (FGID) are common among children and may cause a significant symptom burden. The Rome criteria are symptom-based guidelines for the assessment of FGID among children and adults. The aim of this systematic review was to estimate the prevalence of FGID utilizing the revised Rome IV criteria. Nine health databases were searched. The inclusion criteria were: prospective FGID prevalence data using the Rome IV criteria for children up to 18 years, and the exclusion criteria were: cohorts with known gastrointestinal or organic conditions. The data were presented as a percentage of children experiencing at least one FGID, as well as in individual categories. The searches identified 376 papers, with 20 included in the final analysis, providing a pooled cohort of 18,935 children. The median prevalence of FGID for children aged up to four years was 22.2% (range 5.8-40%), and aged four-eighteen years was 21.8% (range 19-40%). The most common FGID for children aged 0-12 months was infant regurgitation, the most common FGID for those aged 13-48 months were functional constipation and cyclic vomiting, and, for those aged over four years, functional constipation, functional dyspepsia, and irritable bowel syndrome. This reported overall incidence of FGID may be used as a benchmark of normative data among the general population and comparative data for those with comorbid disease.

Targeting ion channels for the treatment of gastrointestinal motility disorders

Gastrointestinal (GI) functional and motility disorders are highly prevalent and responsible for long-term morbidity and sometimes mortality in the affected patients. It is estimated that one in three persons has a GI functional or motility disorder. However, diagnosis and treatment of these widespread conditions remains challenging. This partly stems from the multisystem pathophysiology, including processing abnormalities in the central and peripheral (enteric) nervous systems and motor dysfunction in the GI wall. Interstitial cells of Cajal (ICCs) are central to the generation and propagation of the cyclical electrical activity and smooth muscle cells (SMCs) are responsible for electromechanical coupling. In these and other excitable cells voltage-sensitive ion channels (VSICs) are the main molecular units that generate and regulate electrical activity. Thus, VSICs are potential targets for intervention in GI motility disorders. Research in this area has flourished with advances in the experimental methods in molecular and structural biology and electrophysiology. However, our understanding of the molecular mechanisms responsible for the complex and variable electrical behavior of ICCs and SMCs remains incomplete. In this review, we focus on the slow waves and action potentials in ICCs and SMCs. We describe the constituent VSICs, which include voltage-gated sodium (Na(V)), calcium (Ca(V)), potassium (K(V), K(Ca)), chloride (Cl(-)) and nonselective ion channels (transient receptor potentials [TRPs]). VSICs have significant structural homology and common functional mechanisms. We outline the approaches and limitations and provide examples of targeting VSICs at the pores, voltage sensors and alternatively spliced sites. Rational drug design can come from an integrated view of the structure and mechanisms of gating and activation by voltage or mechanical stress.