Study	Reason for exclusion
Allahdin 2008	RCT evaluating the 3 surgical techniques for pelvic organ prolapse surgery. Pelvic organ prolapse data were grouped, and data specific to posterior prolapse were not available.
Boccasanta 2004	RCT on 2 transanal stapled techniques for outlet obstruction. Outlet obstruction caused not only by rectoceles but also by descending perineum and intussusception. Prolapse data not explicitly presented
Boccasanta 2011	RCT investigating clinical and functional outcomes of the stapled transanal rectal resection in patients with obstructed defecation caused by rectal intussusception and rectocele. Participants with rectal intussusception and rectocele were grouped together, and rectocele data were not explicitly presented.
Dahlgren 2011	RCT comparing use of a porcine skin graft (Pelvicol) vs conventional colporrhaphy in recurrent pelvic organ prolapse surgery. Data regarding participants with cystocele and rectocele were presented together, and information specific to rectocele was not explicitly presented.
Derpapas 2013	Study comparing posterior colpoperineorrhaphy or fascial and vaginal epithelial plication (FEP) of the posterior vaginal wall. Participants were already included in the Vijaya study.
Detollenaere 2013	Study comparing sacrospinous hysteropexy (SH) against vaginal hysterectomy in patients with uterine descent POP‐Q stage > 2. Study was not included because patients with anterior and posterior vaginal wall prolapse were grouped together. Posterior prolapse data were not explicitly presented.
Gentile 2014	Study comparing effectiveness and safety of endorectal proctopexy against the STARR procedure in patients with mucosal prolapse or anorectal intussusception (types of rectal prolapse) rather than vaginal prolapse
Glazener 2016	Study looking at clinical effectiveness and cost‐effectiveness when comparing surgical methods of vaginal wall prolapse. No data on pelvic organ prolapse were given.
Leanza 2013	Quasi‐randomised controlled trial
Lehur 2008	RCT not comparing 2 surgical techniques. Study compared conservative management vs surgical management of rectal mucosal prolapse, which is not the topic of our meta‐analysis.
Liu 2016	RCT focusing on treatment of obstructed bowel syndrome associated with rectocele and internal rectal intussusception. The 2 pathologies were not differentiated. Trial concerned 2 different transanal approaches to deal primarily with rectal mucosal prolapse.
Mahmoud 2012	RCT evaluating transanal repair with and without use of a stapler for the procedure. This comparison is not relevant to our meta‐analysis.
Noe 2014	RCT comparing pectopexy with sacral colpopexy for correction of vaginal prolapse POP‐Q stage 2 or greater. Data for posterior vaginal prolapse were not available as this was grouped broadly with anterior and apical prolapse.
Nygaard 2013	RCT investigating anatomic and symptomatic outcomes of abdominal sacrocolpopexy. Study was not included because patients with anterior and posterior vaginal wall prolapse were grouped together. Data for posterior wall prolapse could not be separated from rest of trial data.
Svabik 2016	RCT investigating 2 surgical procedures for post‐hysterectomy vaginal vault prolapse (anterior and posterior Prolift mesh vs sacrospinous colpopexy with anterior and/or posterior native tissue vaginal repair). Apical prolapse covered in separate Cochrane review
Tang 2006	Excluded on the basis of comparing 2 different incision techniques for the posterior vaginal wall rather than 2 different repair techniques
Wang 2010	Study investigating the value of co‐treatment with rectal wall repair and procedure for prolapse and haemorrhoids (PPH) for outlet obstruction constipation (OOC) induced by rectocele in woman. This comparison was not relevant to our meta‐analysis.

FEP: fascial epithelial plication.
 OOC: outlet obstruction constipation.
 POP‐Q: Pelvic Organ Prolapse Quantification (according to ICS).
 PPH: procedure for prolapse and haemorrhoids.
 RCT: randomised controlled trial.
 STARR: stapled transanal rectal resection.