Background <p>The intrauterine device (IUD) is an efficient and commonly used long-term contraceptive method. Although generally safe, its rare yet serious complications—uterine perforation and secondary intra-abdominal migration—can lead to injuries to adjacent organs, such as intestinal perforation, obstruction, or necrosis. IUD displacement into the small intestine causing necrosis is an extremely rare clinical event, with limited reports in the literature.</p> Case presentation <p>This report describes an 81-year-old female who was admitted due to upper abdominal pain for one day and had a history of IUD placement. One day prior to admission, the patient developed persistent upper abdominal pain accompanied by nausea, vomiting, and cessation of flatus and defecation. Computed tomography (CT) suggested intestinal obstruction, with the possibility of IUD displacement and intestinal ischemia. Intraoperatively, it was observed that a segment of the small intestine had become entrapped within a metal contraceptive ring approximately 3&#xa0;cm in diameter, resulting in intestinal ischemia and necrosis. The procedures performed included removal of the contraceptive ring, partial ileal resection with anastomosis, and uterine repair. The patient recovered well postoperatively.</p> Conclusions <p>Although small bowel necrosis caused by IUD displacement is rare, it constitutes a surgical emergency. Clinicians should maintain a high index of suspicion in patients with a history of IUD placement who present with abdominal pain, and promptly conduct imaging evaluation to avoid missed diagnosis and serious consequences.</p> Clinical trial number <p>Not applicable.</p>