An intrauterine device disappeared for nine years: a rare case report and literature review.

Background: The intrauterine device (IUD) displacement into the urinary bladder is an exceedingly rare complication. Given its potential to induce bladder irritation, erosion, or perforation, affected patients may present with lower abdominal pain, abdominal distension, and dysuria. As a result, clinical symptoms often prompt timely diagnosis, leading to early detection in the majority of reported cases. Case presentation: We report a rare case of IUD displacement into the urinary bladder that remained undiagnosed for nine years. Following her fourth IUD insertion, the patient developed lower abdominal pain, right lower limb edema, and impaired mobility; however, these symptoms were erroneously misdiagnosed during ultrasound examination. A definitive diagnosis was not established until nine years later, when she presented anew with persistent lower abdominal pain. Subsequent computed tomography (CT) scan and color Doppler ultrasound confirmed intravesical IUD migration, and the device was successfully retrieved via surgery. Conclusions: This case underscores the critical importance of thorough post-procedural evaluation, particularly in patients who develop new or persistent symptoms following IUD insertion. Furthermore, CT may be useful when ultrasound findings are inconclusive or when extrauterine displacement is suspected.