Rectovaginal fistula

Rectovaginal fistulae are a type of colovaginal fistula where there is an abnormal fistulous connection between the rectum and the vagina. It is considered the most common gastrointestinal fistula involving the female genital tract ¹.

Pathology

They can occur from a number of causes that include:

• complication of childbirth
• pelvic malignancy
• pelvic radiation therapy
• infectious processes within the rectovaginal septum
• operative trauma 
• inflammatory bowel disease, e.g. Crohn disease
• foreign body complication

Radiographic features

This may be seen as direct breach of the wall between the rectum and the vagina. An examination with contrast within the rectum is more helpful to confirm a tract. Fluoroscopy may be used, and an emerging technique is an MRI enema with gel used instead of contrast media. Some authors propose the use of CT vaginography ⁷.

Endoluminal sonography and endoluminal MR imaging are thought to have comparable positive predictive values in revealing the location of rectovaginal fistulas ².

Differential diagnosis

In the case of small amounts of intravaginal gas, this can often be seen with physiological situations ⁶ and rectal contrast examination is often useful for differentiation in clinically suspected cases.

See also

• gut fistulation