Inclusion/ exclusion criteria followed in the search and retrieval of guidelines to be adapted:
· Selecting only evidence-based guidelines (guideline must include a report on systematic literature searches and explicit links between individual recommendations and their supporting evidence)
· Selecting only national and/or international guidelines
· Specific range of dates for publication (using Guidelines published or updated in 2015 and later)
· Selecting peer reviewed publications only
· Selecting guidelines written in English language
· Excluding guidelines written by a single author, not on behalf of an organization to be valid and comprehensive, a guideline ideally requires multidisciplinary input
· Excluding guidelines published without references as the panel needs to know whether a thorough literature review was conducted and whether current evidence was used in the preparation of the recommendations
The following characteristics of the retrieved guidelines were summarized in:
· Developing organization/authors
· Date of publication, posting, and release
· Country/language of publication
· Date of posting and/or release
· Dates of the search used by the source guideline developers
All retrieved Guidelines were screened and appraised using AGREE II instrument (www.agreetrust.org) by at least three members. The panel decided on a cut-off point or ranked the guidelines (any guideline scoring above 50% on the rigor dimension was retained). The GGS decided to adapt the Bologna guidelines for diagnosis and management of adhesive small bowel obstruction (ASBO): 2013 update of the evidence-based guidelines from the World Society of Emergency Surgery ASBO Working Group and guidelines for management of small bowel obstruction, 2008.
Evidence assessment
According to WHO Handbook for Guidelines, we used the GRADE (Grading of Recommendations, Assessment, Development and Evaluation) approach to assess the quality of a body of evidence, develop and report recommendations. GRADE methods are used by WHO because these represent internationally agreed standards for making transparent recommendations. Detailed GRADE information is available on the following sites:
· GRADE working group: https://www.gradeworkinggroup.org/
· GRADE online training modules: http://cebgrade.mcmaster.ca/
Specifically, the quality of evidence was graded as ‘High’, ‘Moderate’, ‘Low’ or ‘Very low’, (table 1& 2).