A 68-year-old male with a history of alcohol abuse presented with a one-week history of fatigue and weakness, and a one-year history of fecal incontinence. On admission, vital signs were stable. Physical exam revealed cachexia, skin pallor, and mild abdominal distention. Fecal occult blood testing was positive. Laboratory analysis was significant for hemoglobin of 6.8g/dL. Of note, computed tomography (CT) scans of his chest, abdomen, and pelvis done months prior for evaluation of anemia and incontinence had shown rectal wall thickening, lung nodules concerning for metastasis, and gallstones. He declined further diagnostic evaluation and was lost to follow up. During current admission for anemia, colonoscopy was performed demonstrating a 15-centimeter rectal mass. Biopsies revealed invasive adenocarcinoma. On hospital day five, he developed severe abdominal pain, distention, and vomiting. Abdominal X-ray showed signs of small bowel obstruction (SBO). He subsequently had abdominal CT, which revealed pneumobilia and calcified stones at the distal small bowel. Findings were consistent with gallstone ileus. He then underwent urgent exploratory laparotomy with small bowel resection and enterolithotomy of the offending gallstone. Intraoperatively, the surgical team encountered bowel wall erosion and a focal, contained perforation with a small abscess. The collection was cultured, and resulted positive for extended spectrum beta-lactamase (ESBL) producing Klebsiella oxytoca. The patient was started on antibiotic therapy and discharged once stable with plans to follow up for treatment of rectal cancer as an outpatient. Gallstone ileus is a rare cause of mechanical SBO, occurring in less than one percent of such cases. CT is the gold standard imaging study for diagnosis. Resuscitation and surgical intervention are treatment mainstays.
Lazar N, Niculescu O, Lima CCV, Lima NA.Gallstone ileus complicating rectal cancer: A red herring cause of abdominal pain. American College of Physicians Michigan Chapter (ACP); 2021, October 14-17, 2021.