A case of obstructed labour which was delivered by caesarian section complains of cyclical passage of menstrual blood in urine. Which is the most likely site of fistula :
**Core Concept**
In obstetric fistula, a communication between the urinary and genital tracts occurs due to prolonged obstructed labour, leading to the passage of menstrual blood in urine. This condition is a result of the damage to the tissues surrounding the urethra and bladder, creating a fistulous tract.
**Why the Correct Answer is Right**
The most common site of a vesicovaginal fistula (VVF) is the posterior wall of the bladder, near the bladder neck. This occurs due to the prolonged pressure of the fetus's head on the bladder and urethra during obstructed labour. The posterior wall of the bladder is the weakest point and is more prone to damage, resulting in a fistulous tract. The passage of menstrual blood in urine is a classic symptom of VVF.
**Why Each Wrong Option is Incorrect**
**Option A:** Vesicourethral fistula is a rare type of fistula and is not typically associated with the passage of menstrual blood in urine.
**Option B:** Ureterovaginal fistula is a type of fistula that occurs between the ureter and vagina, but it is not typically associated with the passage of menstrual blood in urine.
**Option C:** Rectovaginal fistula is a type of fistula that occurs between the rectum and vagina, and is not associated with the passage of menstrual blood in urine.
**Clinical Pearl / High-Yield Fact**
Obstructed labour is a leading cause of vesicovaginal fistula worldwide. Early recognition and prompt surgical intervention can prevent the development of this condition.
**Correct Answer: C. Rectovaginal fistula is a type of fistula that occurs between the rectum and vagina, and is not associated with the passage of menstrual blood in urine.