Pediatric bladder injuries, though uncommon, typically result from blunt trauma, often associated with motor vehicle collisions. While most bladder injuries are linked to pelvic fractures, this association may be less common in children due to anatomical differences. Bladder injuries are classified as extraperitoneal, intraperitoneal, or combined, with intraperitoneal injuries being rarer but more prevalent in children due to their higher abdominal bladder position. This case report discusses a rare instance of delayed intraperitoneal bladder rupture in a young child following a relatively minor fall, emphasizing diagnostic challenges.

A 4-year-old female presented with new onset abdominal pain, vomiting, and subjective fever three days after a minor fall. Initial evaluation revealed diffuse abdominal tenderness, elevated creatinine, and moderate ascites on ultrasound with no gross hematuria. Despite treatment for presumed acute kidney injury, the patient's condition worsened, leading to the identification of a large posterior dome bladder rupture via cystography. Surgical repair was performed, and the patient was discharged with a full recovery after sequential removal of urinary catheters.

Intraperitoneal bladder rupture can occur in healthy children after minor trauma and may not present acutely with the classic signs of gross hematuria and peritonitis. Emergency physicians should consider this diagnosis in young children with unexplained ascites, abdominal pain, hematuria, and renal failure, even with only a remote history of minor abdominal trauma.