Abstract
Hydrocolpos is the distension of the vagina caused by accumulation of fluid due to congenital vaginal obstruction. The obstruction is often caused by an imperforate hymen or less commonly a transverse vaginal septum. The fluid consists of cervical and endometrial mucus or in rare instances urine accumulated through a vesicovaginal fistula proximal to the obstruction. In some cases it is associated with Bardet-Biedl Syndrome. If it occurs in prepubertal girls, it may show up as abdominal swelling. It may be detected by using ultrasound. It may also present at birth as a distended lower abdomen and vagina. It also associated with vaginal atresia.