RESUMO
INTRODUCTION AND IMPORTANCE: Biliary ileus is a rare yet significant cause of mechanical intestinal obstruction, which occurs when a gallstone enters the gastrointestinal tract through a bilioenteric fistula, leading to intestinal blockage. This condition primarily affects elderly patients and is associated with high morbidity and mortality if not diagnosed and treated promptly. CASE PRESENTATION: We present the case of a 94-year-old female with a history of hypertension and chronic venous insufficiency. The patient was admitted with severe abdominal pain, nausea, and vomiting, with clinical findings suggestive of intestinal obstruction. Computed tomography revealed Rigler's triad, confirming the diagnosis of biliary ileus. An exploratory laparotomy was performed, identifying three gallstones in the small intestine. The patient underwent enterotomy for stone extraction and had a favorable immediate postoperative outcome. CLINICAL DISCUSSION: Biliary ileus presents a diagnostic challenge due to its nonspecific symptoms. While Rigler's triad (pneumobilia, intestinal obstruction, and ectopic gallstone) is diagnostic, it is not always apparent in imaging. Surgical intervention remains the standard of care for resolving the obstruction, though appropriate preoperative management and timely surgery are crucial for improving outcomes. CONCLUSION: This case emphasizes the importance of considering biliary ileus in the differential diagnosis of intestinal obstruction, particularly in elderly patients. Early surgical intervention is essential to prevent severe complications. Evidence based medicine ranking: Level IV.