Surgery for constipation: systematic review and clinical guidance: Paper 1: Introduction & Methods.

AIM: This manuscript provides the introduction and detailed methodology used in subsequent reviews to assess the outcomes of surgical interventions with the primary intent of treating chronic constipation in adults and to develop recommendations for practice.

METHOD: PRISMA guidance was adhered to throughout. A literature search was performed in public databases between January 1960 and February 2016. Studies that fulfilled strictly-defined PICOS (patients, interventions, controls, outcome, and study design) criteria were included. The process involved two groups of participants: (i): 'a clinical guidance group' of 18 UK experts (including junior support) who performed the systematic reviews and produced summary evidence statements (SES) based strictly on data synthesis in each review. The same group then produced prototype graded practice recommendations (GPRs) based on coalescence of SES and expert opinion; (ii): a European Consensus group of 18 ESCP (European Society of Coloproctology) nominated experts from nine European countries evaluated the appropriateness of each prototype GPR based on published RAND/UCLA methodology.

RESULTS: An overview of the search results is provided in this manuscript. A total of 156 studies from 307 full text articles (from 2551 initially screened records) were included, providing data on procedures characterized by: (i) colonic resection (n = 40); (ii) rectal suspension (n = 18); (iii) rectal wall excision (n = 44); (iv) rectovaginal septum reinforcement (n = 47); (v) sacral nerve stimulation (n = 7). The overall quality of evidence was poor with 113/156 (72.4%) studies providing only Oxford level IV evidence. The best evidence was extracted for rectal excisional procedures, where the majority of studies were Oxford level I or II. The five subsequent reviews provide a total of 99 SES (reflecting perioperative variables, efficacy, harms and prognostic variables) that contributed to 100 prototype GPRs covering patient selection, procedural considerations and patient counselling. The final manuscript details the 85/100 GPRs that were deemed appropriate by European Consensus (remaining 15 were all uncertain) and future research recommendations.

CONCLUSION: This manuscript and the following 6 papers suggest that the evidence base for surgical management of chronic constipation is currently poor although some expert consensus exists on best practice. Further studies are required to inform future commissioning of treatments and of research funding.