Clinical overview
A gynaecological fistula is an abnormal, epithelialised communication between the genital tract and an adjacent hollow viscus — most often the urinary tract (bladder, ureter, urethra) or the bowel (rectum, colon). The cardinal symptom is continuous, uncontrollable leakage of urine or faeces into the vagina which — unlike stress or urgency incontinence (Urinary incontinence) — is constant and unrelated to effort or urge. Beyond the physical morbidity (perineal excoriation, recurrent infection, stone formation, odour), fistulae are socially catastrophic: in the obstetric setting they cause profound stigma, isolation, loss of livelihood, divorce and destitution, which is why obstetric fistula is treated as a maternal-health and human-rights priority as much as a surgical problem. The global burden remains large — hundreds of thousands of women live with untreated obstetric fistula, overwhelmingly in low-resource settings, and it is a marker of inequitable access to emergency obstetric care.
Because this is a pathology/pathophysiology objective, the emphasis here is on how fistulae form, the tissue events that produce them, where they occur, and how they are classified — the foundation that explains both prevention and repair. The single most important conceptual divide is between the obstetric fistula (ischaemic-pressure necrosis from obstructed labour, the dominant cause in low-resource settings) and the iatrogenic/surgical fistula (sharp or thermal injury, the commoner cause in better-resourced settings, including much of urban South Africa). This chapter links to Urinary incontinence (the key differential), Urinary retention, and the obstetric prevention context of Safe caesarean technique.
Core knowledge
Types by anatomical communication
Figure C4.1 — The fistula map: types named by the organs they connect (vesicovaginal, ureterovaginal, urethrovaginal, vesicouterine/Youssef, rectovaginal), with the key discriminating features of each.
- Vesicovaginal fistula (VVF) — bladder to vagina; the commonest urogenital fistula; continuous urinary leakage per vaginam with, in larger fistulae, little or no normal voiding.
- Ureterovaginal fistula — ureter to vagina; classically continuous leakage with preserved normal voiding (the contralateral ureter still drains the bladder normally); almost always iatrogenic after pelvic surgery.
- Urethrovaginal fistula — urethra to vagina; leakage, spraying on voiding, or asymptomatic if proximal and small; if it involves the continence mechanism, repair may not restore continence.
- Vesicouterine fistula — bladder to uterus; a recognised complication of caesarean section, classically presenting with cyclical haematuria (menouria), amenorrhoea and urinary continence — the triad of Youssef syndrome.
- Rectovaginal fistula (RVF) — rectum to vagina; passage of flatus or faeces per vaginam; from obstetric anal-sphincter injury (OASIS), obstructed labour, surgery, Crohn's disease, or malignancy.
- Complex/combined — large obstetric fistulae may involve bladder, urethra and rectum together, with extensive circumferential tissue loss.
Pathophysiology by cause
