Defining and evaluating pouch anal and vaginal fistula

To see our latest courses, or to donate to the St Mark's Hospital Foundation, please visit our channel description for details. Title: Defining and evaluating pouch anal and vaginal fistula Speaker: Lillian Reza Event: St Mark's Academic Institute Grand Round Year: 2026 This PhD research addresses the significant clinical challenge of pouch anal and pouch vaginal fistulas, a serious complication following ileal pouch–anal anastomosis (IPAA), associated with substantial morbidity and a high risk of pouch failure. Historically, inconsistent definitions, limited evidence and an over-reliance on the timing of fistula presentation have contributed to misdiagnosis, inappropriate treatment and considerable variation in clinical practice. The research developed and retrospectively evaluated the St Mark’s Perianal Pouch Fistula Classification, categorising fistulas according to aetiology: anastomotic leak, inflammatory bowel disease (IBD), cryptoglandular disease and malignancy. The findings demonstrated that timing of presentation does not reliably determine aetiology, while aetiology is strongly associated with clinical outcomes, particularly pouch failure. Accurate classification can therefore inform prognosis and guide appropriate treatment, including avoiding biologic therapy in patients with fistulas arising from anastomotic complications. A further study identified MRI features associated with mucinous adenocarcinoma arising within pouch fistulas. Features including budding, mass-like expansion and septation may precede histological diagnosis, highlighting the importance of targeted biopsy and continued surveillance when malignancy is suspected. Recognising the previously under-represented patient perspective, qualitative interviews explored the physical, psychological and social burden of fistulas, including pain, discharge, impaired daily functioning, relationship difficulties and fear of pouch loss. These findings informed the development of a core outcome set for pouch fistula research and the 14-item Pouch Fistula Quality of Life Scale (PACL-14), providing a disease-specific measure of patient-reported outcomes. Finally, a multidisciplinary expert consensus study used the RAND/UCLA methodology to develop evidence-informed management recommendations. These emphasise comprehensive investigation, early control of sepsis, treatment tailored to aetiology, cautious use of biologics and shared decision-making regarding surgical intervention and pouch preservation. Overall, this work establishes a framework for improving classification, diagnosis, treatment and outcome measurement. Despite limitations associated with retrospective data, small patient numbers and tertiary centre referral bias, it provides a foundation for prospective multicentre validation and more consistent, patient-centred care.