Lower Abdominal Pain in a Perimenarchal Adolescent.

A 13-year-old girl presented to the emergency department with a 5-day history of lower abdominal pain and dysuria that coincided with the onset of her last menstrual period. Menarche occurred 4 months previously and previous cycles were normal. The CAT scan of the abdomen and pelvis revealed a uterus didelphis with obstruction. Abdominal pain was due to hematocolpos and hematometra. The left hemivagina was distended with hematocolpos, and left renal agenesis was also noted. The vaginal septum was removed surgically without complications and she continued to be monitored closely.