• The causes of recto-vaginal fistulas include Crohn’s disease, diverticulosis, recent surgery (ileo-anal reservoir) or following vaginal delivery.
   
• Contrast used is either water soluble contrast or dilute (30% w/v) barium.

Equipment:

• Rectal tube (do not inflate balloon) or a 14-18 F Foley catheter
   
• You can use a pediatric (blue) barium enema tube
   
• Barium: Use 50% Diluted Polibar (100% w/v)
   
• You can use air for double contrast (i.e. for mucosal disease)

Technique:

• Scout radiographs AP and lateral view.
   
• A small Foley catheter is used with the balloon not being inflated (to detect very low ano-vaginal fistulas).
   
• Controlled hand instillation of contrast is the best technique to detect and locate the exact site of the fistula.
   
• Sometimes a Valsalva maneuver can uncover small fistulas.

Radiographs:

SCOUT LATERAL VIEW: This will assess if there is any air in the vagina. Do NOT inflate the balloon as this will obscure the fistula.	SCOUT AP VIEW: Dilute barium (30-05 % w/v dilution of Polibar 100%) or 30-60% Hypaque contrast can be used.
LATERAL VIEW: This is the most important view.  The early filling phase should be done carefully and using fluoroscopy to detect the ano-vaginal fistula early.	OBLIQUE VIEW: This view will help detect some of the unusual leaks along the lateral aspect of the ano-rectal junction.
AP VIEW: Sometimes introducing air can show the fistula better.	SPECIAL MANUVERS: Withdraw the rectal tube down to anus & have patient perform the Valsalva maneuver.
SPECIAL MANEUVERS (LATERAL VIEW): Remove the rectal tube and ask the patient to perform the Valsalva maneuver.	SPECIAL MANEUVERS (AP VIEW): Remove the rectal tube and ask the patient to perform the Valsalva maneuver.