Ruey Terng Ng, Way Seah Lee, Hak Lee Ang, Kai Ming Teo, Yee Ian Yik, Nai Ming Lai

Childhood constipation is a common problem with substantial health, economic and emotional burdens. Existing therapeutic options, mainly pharmacological, are not consistently effective, and some are associated with adverse effects after prolonged use. Transcutaneous electrical stimulation (TES), a non-pharmacological approach, is postulated to facilitate bowel movement by modulating the nerves of the large bowel via the application of electrical current transmitted through the abdominal wall. Our main objective was to evaluate the effectiveness and safety of TES when employed to improve bowel function and constipation-related symptoms in children with constipation. We searched MEDLINE (PubMed) (1950 to July 2015), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 7, 2015), EMBASE (1980 to July 2015), the Cochrane IBD Group Specialized Register, trial registries and conference proceedings to identify applicable studies . Randomized controlled trials that assessed any type of TES, administered at home or in a clinical setting, compared to no treatment, a sham TES, other forms of nerve stimulation or any other pharmaceutical or non-pharmaceutical measures used to treat constipation in children were considered for inclusion. Two authors independently assessed studies for inclusion, extracted data and assessed risk of bias of the included studies. We calculated the risk ratio (RR) and corresponding 95% confidence interval (CI) for categorical outcomes data and the mean difference (MD) and corresponding 95% CI for continuous outcomes. We evaluated the overall quality of the evidence supporting the outcomes assessed in this review using the GRADE criteria. One study from Australia including 46 children aged 8 to 18 years was eligible for inclusion. There were multiple reports identified, including one unpublished report, that focused on different outcomes of the same study. The study had unclear risk of selection bias, high risks of performance, detection and attrition biases, and low risks of reporting biases.We are very uncertain about the effects of TES on bowel movements, colonic transit, soiling symptoms and quality of life due to high risk of bias, indirectness and imprecision. For our outcomes of interest the 95% CI of most analysis results include potential benefit and no effect. There is insufficient evidence to determine the effect of TES on bowel movements and colonic transit. The study reported that 16/21 children in the TES group and 15/21 in the sham group had > 3 complete spontaneous bowel movements (CSBM) per week (RR 1.07, 95% CI 0.74 to 1.53; very low-quality evidence). Ten out of 14 children in the TES group had improved colonic transit compared to 1/7 in the sham group (RR 5.00, 95% CI 0.79 to 31.63; very low-quality evidence). Mean colonic transit rate, measured as the position of the geometric centre of the radioactive substance ingested along the intestinal tract, was higher in children who received TES compared to sham (MD 1.05, 95% CI 0.36 to 1.74; one study, 30 participants; very low-quality evidence). The radiological assessment of colonic transit outcomes means that these results might not translate to important improvement in clinical symptoms or increased bowel movements. There is insufficient evidence to determine the effect of TES on symptoms and quality of life (QoL) outcomes. Nine out of 13 children in the TES group had improved soiling-related symptoms compared to 4/12 sham participants (RR 2.08, 95% CI 0.86 to 5.00; very low-quality evidence). Four out of 8 TES participants reported an improvement in QoL compared to 1/8 sham participants (RR 4.00, 95% CI 0.56 to 28.40; very low-quality evidence). The effects of TES on self-perceived (MD 5.00, 95% CI -1.21 to 11.21; one study, 33 participants; very low-quality evidence) or parent-perceived QoL (MD -0.20, 95% CI -7.57 to 7.17, one study, 33 participants; very low-quality evidence) are uncertain. No adverse effects were reported in the included study. The results for the outcomes assessed in this review are uncertain. Thus no firm conclusions regarding the efficacy and safety of TES in children with chronic constipation can be drawn. Further randomized controlled trials assessing TES for the management of childhood constipation should be conducted. Future trials should include clear documentation of methodologies, especially measures to evaluate the effectiveness of blinding, and incorporate patient-important outcomes such as the number of patients with improved CSBM, improved clinical symptoms and quality of life.