A 42-year-old woman who underwent a difficult vaginal delivery 2 weeks ago reports continuous leakage of urine per vaginam day and night, though she voids normally as well. Which bedside test localises the fistula?

• A Marshall-Marchetti test
• B Bonney's test
• C Q-tip test
• D Three-swab test with methylene blue instilled into the bladder ✓

Explanation

Continuous urinary leakage soon after obstructed labour suggests vesicovaginal fistula. In the three-swab test, three swabs are placed in the vagina and methylene blue is instilled into the bladder: staining of the uppermost swab blue indicates a vesicovaginal fistula, while a wet but unstained upper swab with clear wetting from above suggests a ureterovaginal fistula. Bonney's and Q-tip tests assess stress incontinence, which causes leakage on exertion rather than continuous loss, distinguishing them clinically from a fistula.

Reference: Bailey and Love's Short Practice of Surgery, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.