This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous (Obs), Subject name: Gynaecology & Obstetrics
[{'content': 'Investigation of Choice for Vesico-Vaginal Fistula is: \nSelect and explain. \nA. IVP, B. Cystoscopy, C. 3 Swab Test, D. X ray', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. (c) 3 Swab TestRef: Shaws Textbook of Gynecology 16th Ed; Page No-222Vesicovaginal Fistula (VVF)* Most common cause of bladder fistulae (80-90%) in India:Obstetrical problem.# Prolonged labour-- operative--vaginal caesarean section.* Sometime gynaecological cause:# Hysterectomy# Sling operations for stress incontinence* Clinical features: Continuous dribbling of urine--no micturition (true incontinence).* Investigation: Methylene swab test.# The vaginal cavity is packed with three sterile swabs; 50-100mL of dilute methylene blue dye is injected into the bladder through the catheter.# If there is a VVF present, the methylene blue dye stains the uppermost swab.* IVP: Normal in Vesicovaginal Fistula (VVF), but Hydronephrosis on the affected side seen in Ureteric Fistula.', 'role': 'assistant'}]