In real life
A 3‑year‑old girl is constantly damp despite being toilet‑trained. Ultrasound shows her left kidney has two parts, with a dilated upper part and its ureter ending in a cyst‑like swelling in the bladder (ureterocele). Her extra ureter drains below the bladder neck, causing constant dribbling. A duplex kidney, explained by the Weigert–Meyer rule.