Types of studies

Randomized controlled trials (RCTs) without language constraints comparing acupoint stimulation with no treatment, placebo, sham acupuncture or conventional medical treatment will be considered for inclusion. We will also include combined therapy with acupoint stimulation and conventional medical treatment compared with conventional medical treatment in RCTs. Quasi‐randomized trials or controlled trials using any other non‐random allocation methods will be excluded.

Types of participants

Participants of over 18 years of age following open or laparoscopic gastrointestinal surgery , regardless gender, regardless emergency or elective surgery, will be included.

Types of interventions

In this review acupoint stimulation will be limited to the stimulation of acupoints by needling acupuncture, moxibustion, ear acupuncture, electro‐acupuncture, acupoint injection, acupressure, or catgut embedding at acupoints. 

Control intervention will be the following methods alone or combined with the same intervention with the intervention group(s):

•   no treatment

•   placebo

•   sham acupuncture

•   conventional medication treatment

Types of outcome measures

Electronic searches

We will search Pubmed (1966 to present), MEDLINE (1950 to present), EMBASE (1974 to present), the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library 2012, Issue 3) , China Network Knowledge Infrastructure (CNKI) (1911‐1978, 1979‐2012), Wan Fang Database (1985‐2012), VIP Database for Chinese Technical Periodicals (VIP) (1989‐2012), Chinese Biomedical Database (CBM) (1978‐2012).   

For our PUBMED, MEDLINE and CENTRAL searches, we will search the following terms as both free‐text terms as well as MeSH terms: (acupuncture; acupuncture therapy; auricular acupuncture (free text only); acupressure (free text only); acupoint injection (free text only); acupoint catgut embedding (free text only); electroacupuncture; moxibustion; Medicine, Oriental Traditional; Medicine, Chinese Traditional) AND (ileus; postoperative ileus(free‐text only); postoperative complications(free‐text only) AND (gastrointestinal (free text only); Digestive System Surgical Procedures(MeSH) )). For our EMBASE search, we will use a modified version of the MEDLINE strategy (Appendix 1).

Searching other resources

Reference lists of published papers and minutes of the meetings will be screened and grey literature will be searched through Google. 

Selection of studies

Two reviewers (Lingshu Wang, Xun Li) will check the titles and abstracts of trials independently. We will retrieve the full‐text articles if necessary. In case of disagreement between the two reviewers, they will reach an agreement with a third author.

Data extraction and management

Two reviewers (Xun Li & Mei Han) will extract data from the included trials independently. Data will be extracted by using a self‐ developed data extraction form. Two reviewers (Lingshu Wang and Mei Han) will check and enter data into RevMan 5.1. Data extraction will include authors, title of study, and the year of publication. The extracted data will also include:

• study design,

• disease,

• sample

• study size,

• treating process,

• type of control interventions,

• the time to first passage of flatus and faeces,

• the length of hospital stay ,

• complications related to diseases and adverse events.

Data on acupuncture treatment extracted will include:

• type of acupoint stimulation

• frequency of treatment

• the duration of treatment

• the length of every treatment

• the number of points use

• qualification of acupuncturists

Assessment of risk of bias in included studies

Methodological quality of RCTs will be assessed independently by at least two reviewers using the criteria in the Cochrane Handbook for Systematic Reviews of Interventions 5.0.0 (Higgins 2008). There are three potential responses: yes, no, and unclear. "Yes" means a low risk of bias and "no" means a high risk of bias. "Unclear" means that insufficient detail is reported in the study. 

The following characteristics will be assessed: sequence generation, allocation concealment, blinding (or masking), incomplete data assessment, selective outcome reporting, other sources of bias. The risk of bias will be assessed using the criteria described in the Cochrane Handbook for Systematic Reviews of Interventions 5.0.0 (Higgins 2008).

Measures of treatment effect

Statistical analysis will be performed using the Review Manager software (version 5.1.6). We will present continuous data as mean differences (MD) with 95% confidence intervals (CI), or use risk ratio (RR) with 95% CI for binary outcomes. Meta‐analysis will be used if the trials have a good homogeneity on study design, participants, interventions, control, and outcome measures.

Unit of analysis issues

We will only include RCTs in which the participants are individually randomised into the clinical trials.

Dealing with missing data

Strategies for dealing with missing data will be described principally including missing participants due to drop‐out whether an intention‐to‐treat analysis will be conducted,and missing statistics (such as standard deviations or correlation coefficients). We will contact the study author who will be asked to provide missing data. The extent and implications of missing data will be reported and discussed in the review. When significant heterogeneity is identified (defined as P value less than 0.1), we will apply random‐effects model for meta‐analysis, otherwise fixed‐effect model will be used.

Assessment of heterogeneity

The I² statistic will be used to assess the degree of statistical heterogeneity.  If I² is higher than 50%, we will consider the heterogeneity as significantly high. When significant heterogeneity is identified, the random‐effects model will be used in the meta analysis, otherwise the fixed‐effect model will be used. Clinical heterogeneity will be considered in relation to the different stimulation methods.

Assessment of reporting biases

Funnel plots will be used to investigate the reporting and associated publication biases.

Data synthesis

We will use RevMan 5.1.6 to perform meta‐analysis if studies are sufficiently similar.

Subgroup analysis and investigation of heterogeneity

Heterogeneity arising from the form of surgery, clinical differences and methodology differences will be considered in this review. If statistical heterogeneity is observed, then the possible reasons for differences will be explored and a decision made about if and how it is appropriate to do the subgroup analysis.

Sensitivity analysis

Sensitivity analyses would be performed to assess trial methodological quality by means of excluding trials with inadequate or unclear randomizations generation, allocation concealment or by excluding trials in which outcome evaluation was not blinded. If sensitivity analysis results differ substantially, the final results will undergo careful interpretation.