S4946 Between Two Strictures: A Rare Case of Enterolith Formation in Longstanding Crohn's Disease

Introduction: Crohn's disease is a chronic inflammatory condition that can lead to stricturing and penetrating complications. Enterolith formation, while more commonly reported in small bowel diverticula and gallstone disease, represents an exceptionally rare complication in Crohn's disease. The unusual nature of this complication and its management challenges warrant documentation to enhance clinical awareness. Case Description/Methods: A 73-year-old man with Crohn's ileitis diagnosed in 1978 and ileal resection in the 1980s presented with recent changes in bowel habits. He had been without medical therapy for approximately 30 years. He reported diarrhea with 4-5 loose bowel movements daily but denied abdominal pain, weight loss, or hematochezia. Imaging revealed a 2.5 cm calcified structure within the mid-distal ileum with associated wall thickening. Colonoscopy was normal with biopsies showing no active inflammation. Magnetic resonance enterography confirmed the intraluminal calcified structure with inflammatory changes proximal and distal to it. Surgical intervention was recommended based on risk for future obstruction, fibrotic strictures unlikely to resolve with medical therapy, concern for potential malignancy, and technical challenges of endoscopic removal. The patient underwent laparoscopic small bowel resection. Two strictures were identified within 4 cm of each other in the mid ileum with a palpable foreign body between them. An approximately 15 cm segment of ileum was resected. Pathology confirmed Crohn's disease with 2 stenoses and a 2.5 cm dark green calculus. The patient had an uneventful recovery. Discussion: The pathophysiology of enterolith formation involves salt precipitation in areas of intestinal stasis, particularly in the alkaline small bowel environment. This case featured an enterolith trapped between 2 closely positioned strictures in a patient who had minimal symptoms for decades before developing diarrhea. Diagnostic imaging initially raised consideration of gallstone ileus. However, the absence of pneumobilia on imaging, along with the patient's remote cholecystectomy history and the characteristic position between 2 inflammatory strictures, all supported a primary enterolith rather than a migrated gallstone. Surgical intervention proved highly effective when faced with anatomical complexity that limited endoscopic options. This case highlights a rarely reported complication of Crohn's disease and the importance of considering the pathophysiology and anatomical features in management.