From Chronic Gallstone to Acute Ileus: A Case Report.

Gallstone ileus is an uncommon cause of mechanical bowel obstruction, often presenting a diagnostic challenge due to its nonspecific symptoms and the variable presence of Rigler's triad (pneumobilia, small bowel obstruction, and ectopic gallstone). We report a case of an 80-year-old female who presented to the emergency department with a two-week history of vague abdominal pain. An initial CT scan revealed mild pneumobilia and a 2 cm calcified mass in the distal small bowel. The diagnosis of gallstone ileus was not initially apparent but was established after reviewing a previous CT scan that showed an identical large mass in the gallbladder. The patient underwent robotic exploration and enterotomy, resulting in the removal of a 4 cm gallstone. This case underscores the importance of reviewing historical imaging in diagnosing gallstone ileus. While Rigler's triad (pneumobilia, small bowel obstruction, and ectopic gallstone) is not always fully present, partial findings should raise suspicion. The unified electronic medical record (EMR) system played a crucial role in expediting the diagnosis by facilitating access to previous imaging studies. This report highlights the value of correlating current and historical imaging findings in diagnosing gallstone ileus, particularly in elderly patients with nonspecific abdominal symptoms. Future educational efforts should focus on increasing awareness of gallstone ileus among emergency physicians and radiologists, emphasizing the importance of correlating current findings with historical imaging data.