Case Report: A typical, nearly missed jejunal gallstone ileus.

Background: Gallstone ileus is a rare cause of mechanical intestinal obstruction, predominantly affecting older adults. The ileum and ileocecal valve are the most common sites of impaction, whereas jejunal involvement is considerably less frequent. Contrast-enhanced computed tomography (CT) is the primary imaging modality for diagnosis; however, minimally calcified ectopic stones are prone to being overlooked, leading to delayed surgical intervention. Case presentation: A 68-year-old woman presented with a 12-day history of abdominal pain, nausea, vomiting, and obstipation. She underwent two contrast-enhanced abdominal CT scans at different institutions, both of which demonstrated cholelithiasis, pneumobilia, and small bowel dilation, but failed to definitively identify an obstructive gallstone. Nevertheless, the combination of pneumobilia and small bowel obstruction-both components of Rigler's triad-along with a visible cholecystoduodenal fistula, made gallstone ileus highly suspected. Emergency exploratory laparotomy revealed a 3.0 × 2.5 cm rim-calcified stone lodged in the jejunum, 80 cm distal to the ligament of Treitz. Simple enterolithotomy was performed without fistula repair. The patient recovered gradually, though she developed transient postoperative atrial fibrillation with hypotension on Day 21, which was managed medically. She was discharged on Day 30. Retrospective re-evaluation of the CT images confirmed the subtle rim-calcified stone. Conclusions: Minimally rim-calcified stones are easily missed on contrast-enhanced CT. In patients with intestinal obstruction exhibiting two of the three signs of Rigler's triad, gallstone ileus should be strongly suspected even when no ectopic stone is clearly visible. Proactive clinician-radiologist communication and structured follow-up planning are essential to reduce diagnostic errors and manage recurrence risk.