aberrant connection between bowel and vagina
| Risk factors | • Pelvic radiation • Obstetric trauma (3rd or 4th degree perineal laceration • Pelvic surgery • Colon cancer • Diverticulitis • Crohn disease | | --- | --- | | Clinical features | • Uncontrollable passage of gas &/or feces from the vagina • malodorous, tan-brown vaginal discharge and a posterior vaginal lesion | | Diagnostic studies | • Physical examination • Fistulography • Magnetic resonance imaging • Endosonography | | Treatment | • Surgical repair |
Diagnosis is typically clinical and based on visualization of a posterior vaginal defect; for patients with an unclear presentation, imaging may be performed.
The obstructed fetal head exerts pressure on the pelvic bones and causes pressure necrosis of the vaginal wall and bladder, which can result in fistula formation. Vesicovaginal fistulas are most commonly seen in individuals from resource-limited countries, where there is limited access to emergency obstetric care. In contrast, vesicovaginal fistulas in women from resource-rich countries are usually a result of iatrogenic injury (e.g., bladder injury during a hysterectomy).
The diagnosis is confirmed with a double dye test. A test used to evaluate for a vesicovaginal fistula. The bladder is instilled with methylene blue, which dyes the urine blue. The test is considered positive if a tampon inserted into the vagina stains blue, indicating a communication tract between the bladder and vagina.
commonly associated with obstetric trauma or pelvic surgery, patients without these risk factors should be evaluated for additional (likely gastrointestinal) causes.