normal pubertal development without expected menarche As the hematocolpos grows, it can interfere with urination, causing urgency, frequency, or dysuria An abdominal ultrasound can aid in the diagnosis of hematocolpos Although the differential diagnosis for a patient with amenorrhea and a lower abdominal mass on physical examination includes pregnancy or tumors, the characteristic appearance of the introitus covered by a bluish bulging membrane is diagnostic of hematocolpos with imperforate hymen Patients with a high transverse vaginal septum will be more difficult to diagnose because the introitus will appear normal However, palpation of the vagina will demonstrate obstruction, and the cervix will not be palpable The emergency physician should also consider the diagnosis of congenital vaginal obstruction in patients with acute urinary retention Due to chronic intrinsic pressure, patients can have variable degrees of hydroureter or hydronephrosis; rarely, infants will present with respiratory insufficiency or inferior vena cava obstruction because of the large mass While imperforate hymen is usually an isolated anomaly, other types of obstruction, chiefly transverse vaginal septum, are regularly associated with renal malformations, including hypoplastic or single kidneys, and duplicated or ectopic collecting systems; presence of additional anomalies should be considered when this condition is diagnosed Patients with congenital vaginal obstruction need surgical treatment; hymenotomy for an imperforate hymen and excision for a transverse vaginal septum Surgery should be planned urgently for adolescents but can be performed electively for asymptomatic infants and children LABIAL ADHESIONS CLINICAL PEARLS AND PITFALLS Labial adhesions are a common, usually asymptomatic disorder of childhood Treatment is not necessary in asymptomatic cases Manual separation of adhesions should be avoided Labial adhesions are a common disorder of childhood, occurring in approximately 0.6% to 3% of prepubertal girls Labial adhesions are thought to be an acquired disorder classically thought to occur due to a lack of estrogen combined with irritation, often due to poor hygiene, diaper rash, vaginitis, and