The Posterior Fornix Syndrome Is an Important Differential Diagnosis for Interstitial Cystitis/Bladder Pain Syndrome.

Background: The catalyst for this analysis was a statement by Dr. Magnus Fall at a meeting of invited experts in 2020 of IC/BPS (interstitial cystitis/bladder pain syndrome): "A paradigm shift in the understanding of IC/BPS is urgent." This review analyses such a paradigm shift.

Summary: The paradigm shift began with the serendipitous cure of Hunner's lesion in a woman with a diagnosis of posterior fornix syndrome (PFS) and uterine prolapse. Retrospective analysis of surgical data from eight PFS studies reporting pain and urge cure found PFS was consistent with IC/BPS definitions. No Hunner's lesions/ulcers were reported in the eight studies. Anatomical pathways for urge/frequency were consistent with Tanagho's descriptions of normal micturition (albeit prematurely activated); pathways for abnormal emptying/retention were consistent with inability of pelvic muscles to open the posterior urethral wall prior to micturition; pathways for pelvic pain were consistent with de novo impulses from pelvic visceral plexuses caused by unsupported USLs (uterosacral ligaments).

Key messages: As PFS and IC/BPS have similar symptoms, USL repair of prolapse can potentially deliver improvement/cure for urge and pain symptoms, provided diagnostic PFS criteria (e.g., speculum test) for PFS are met. Two hypotheses explain inflammatory end-organ responses observed in Hunner's IC/BPS and offer new research directions.