Examination under anaesthesia for the investigation of high grade internal rectal prolapse - the overlooked investigation

Abstract Aim The accurate diagnosis of high grade internal rectal prolapse (HGIRP) can be challenging. Many sources describe a defaecating protocogram (DPG) as the ‘gold standard’ investigation for the diagnosis of HGIRP. Alternative methods for diagnosis include an examination under anaesthesia (EUA). No data has validated the role of EUA for the investigation of HGIRP. The aim of this study was to assess whether an EUA demonstrated different findings to a DPG and if these findings changed clinical management. Methodology This study was a retrospective review of patients seen between 2014–2022 in a quaternary pelvic floor unit. Patients who had an EUA for the investigation of suspected HGIRP were identified and their clinical examination findings, previous investigations and operative findings were reviewed. Results Forty patients were identified. Thirty-eight were female and there was a median age of 66. At EUA, 30 patients (75%) had a HGIRP and two (5%) had external rectal prolapse (ERP). Of the 32 patients with either a HGIRP or ERP at EUA, 19 had a previous DPG performed. Fifteen (79%) of these DPGs showed no evidence of HGIRP or ERP. Of these 15 patients with HGIRP on EUA with a ‘negative’ DPG for HGIRP all went on to have surgical management of their HGIRP. Conclusions If there is clinical suspicion of HGIRP despite a negative DPG, patients should be a considered for an EUA. A negative DPG should not necessarily exclude HGIRP. These results challenge the position of DPG as the ‘gold standard’ investigation for HGIRP.