A 30-year-old woman presents 4 weeks after a prolonged obstructed labour with continuous urinary incontinence through the vagina. On examination, a fistula is visualized on the anterior vaginal wall. Intravenous indigo carmine is given, and the vaginal packing shows blue staining at the distal end but clear fluid at the proximal end. This finding suggests:

• A Combined vesicovaginal and ureterovaginal fistula ✓
• B Ureterovaginal fistula only
• C Vesicovaginal fistula only
• D Urethrovaginal fistula only

Explanation

Indigo carmine IV is excreted by the kidneys and stains urine blue. Blue staining at the distal end of packing indicates ureteric urine reaching the vagina (ureterovaginal fistula). Clear fluid at the proximal end suggests bladder urine reaching the vagina via a vesicovaginal fistula without dye mixing. Combined fistulas give this pattern. This is distinct from the three-swab test where intravesical methylene blue is used.

Reference: Shaw's Textbook of Gynaecology, 18th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.