Standard stapled transanal rectal resection (STARR) with two PPH-01™ poses some questions regarding the completeness of prolapse resection in patients with obstructed defecation syndrome (ODS) since 20% to 30% of patients have persistent rectocele or rectal intussusception that may impair the physiological recovery of rectal sensitivity. New high-volume (HV) devices, such as CPH34 HV™ and CPH36 SMS™, allow for wider prolapsectomy to be performed and we herein assessed the possibility and safety of a STARR mono-stapler.On May 30th-31st 2011, 13 pigs were selected to undergo standard STARR with two PPH-01™ (n=2) or STARR mono-stapler with one CPH34 HV™ (n=11) at the Experimental Center of Vila do Conde (Portugal); another set of 13 pigs was selected on January 14th-17th 2014 to undergo standard STARR (n=2) or STARR mono-stapler by means of one CPH36 SMS™ (n=11). The length, height, square surface, and volume of resected specimens were intra-operatively assessed. Pigs were monitored for three days before undergoing transrectal sonography and autopsy to check for locoregional complications.CPH36 SMS™ STARR mono-stapler achieved 57% higher volume of prolapsectomy compared to Standard STARR (p=0.008); moreover, surface measures of the specimens of CPH36 SMS™ STARR mono-stapler were significantly higher (length, p=0.003; height, p=0.004; square surface, p=0.002) compared to CPH34 HV™ STARR mono-stapler, with a 97.8% increase of prolapsectomy (p<0.001). No intra- or early postoperative complications occurred. Transrectal sonography and autopsy detected: two (50%) small intra-parietal and two (50%) extra-rectal haematomata after Standard STARR; five small intraparietal (45.5%) and one (9%) extra-rectal haematoma after CPH34 HV™ STARR mono-stapler; three (27.2%) small intraparietal and (27.2%) extra-rectal haematomata after CPH36 SMS™ STARR mono-stapler.CPH36 SMS™ STARR mono-stapler is quite feasible both from the technological and safety standpoint; most importantly, the higher volume of prolapsectomy achievable with CPH36 SMS™ compared to standard STARR with two PPH-01™ might reduce the risk of residual/recurrent prolapse and further improve the clinical efficacy of the STARR procedure.