In a case of incontinence of urine, dye filled into the urinary bladder does not stain the pad in the vagina, yet the pad is soaked with clear urine. Most likely diagnosis is:

Ans. is b, i.e. Ureterovaginal fistulaRef: Dutta Gynae 6th/ed, p420; Shaw 15th/ed, p186In the question: In methylene blue swab test, dye filled in the bladder does not stain the pad in vagina but it is soaked with clear urine which means it is a uretero vaginal fistulaObservationInterpretation1. Upper most swab soaked with urine but unstained with dye2. Upper and lower swab remain dry but the middle swab soaked with dye3. The upper two swab remain dry but lower one soaked with dyeUreterovaginal fistulaQVesicovaginal fistulaQUrethrovaginal fistulaQ