Rectovaginal Fistula Diagnosis and Management

Clinical Presentation and Diagnosis

A woman presenting with stool leaking from the vagina most likely has a rectovaginal fistula, which requires prompt imaging confirmation with MRI pelvis as the preferred diagnostic modality, followed by surgical repair as definitive treatment, according to the American College of Radiology 1
The pathognomonic symptoms that confirm this diagnosis include passage of stool, gas, or odorous mucopurulent discharge from the vagina, often confused with incontinence, as noted by the American College of Radiology 1
Dyspareunia and perineal pain are also common symptoms associated with rectovaginal fistula, as reported by the American College of Radiology 1
Recurrent vaginal infections are a frequent complication of rectovaginal fistula, according to the American College of Radiology 1

Physical examination must determine whether the fistula is high or low, as this dictates surgical approach, as recommended by the American College of Radiology 1
MRI pelvis without and with IV gadolinium contrast provides superior visualization of fistulous tracts and is essential for detecting active inflammation and abscesses, according to the American College of Radiology 1
CT pelvis with IV contrast has comparable diagnostic utility for visualizing fluid collections and fistulous tracts, as noted by the American College of Radiology 1
Fluoroscopic vaginography demonstrates 79% sensitivity and 100% positive predictive value for tract identification, as reported by the American College of Radiology 1
Transrectal ultrasound shows 100% positive predictive value for anorectal opening and 93% for vaginal opening, according to the American College of Radiology 1

Simple fistulas versus complex fistulas require fundamentally different management approaches, as recommended by the American College of Radiology 1
Complex features requiring more aggressive intervention include multiple external openings, high anatomical position, associated pain or fluctuation suggesting abscess, as noted by the American College of Radiology 1

Polymicrobial enteric flora with anaerobes on vaginal culture is highly specific for fistulous bowel communication, according to the American College of Radiology 1
Approximately 11% of rectovaginal fistulas are caused by underlying malignancy, making imaging evaluation for soft tissue mass, wall thickening, or malignant lymphadenopathy crucial, as reported by the American College of Radiology 2, 3
Untreated fistulas can progress to sepsis, making early recognition and treatment crucial, as noted by the American College of Radiology 1