Background <p>Adult intussusception is a rare condition accounting for less than 5% of all intussusceptions, with over 90% of cases associated with an identifiable pathological lead point. Idiopathic presentations are exceptional. This case is reportable due to its unique constellation of features: simultaneous double-site small bowel intussusception, concurrent volvulus, transmural necrosis, and complete absence of any structural pathology in a previously healthy young adult.</p> Case presentation <p>A 26-year-old male presented with a 3-day history of abdominal pain and vomiting. Examination revealed peritonitis, prompting urgent laparotomy. Two independent jejunoileal intussusceptions with volvulus were found, both with transmural ischemic necrosis but without perforation. No pathological lead point was identified. Segmental resections with stapled anastomoses were performed. The postoperative course was uneventful, and follow-up confirmed full recovery without recurrence. Histopathology revealed ischemic necrosis without evidence of neoplasia or infection; cultures were negative.</p> Conclusion <p>This exceptionally rare presentation of idiopathic multifocal jejunoileal intussusception with synchronous volvulus and transmural necrosis demonstrates that life-threatening small bowel emergencies may occur without identifiable structural pathology. In adults with acute peritonitis and suspected intestinal ischemia, surgical exploration should supersede diagnostic imaging, as delayed intervention increases mortality risk. This case challenges the lead-point paradigm and expands the phenotypic spectrum of idiopathic adult intussusception.</p>