Supplementary Material for: Gallstone Ileus Mimicking a Colonic Tumor: A Case Report

Introduction
Gall stone ileus is a rare complication of cholelithiasis which typically presents with obstruction
in the small intestine. However, it can rarely mimic a mass when it presents in unusual sites like
the sigmoid colon as in our case.

Case Presentation
We present a 42-year-old woman with history of bariatric surgery, diverticulitis status post
sigmoid colectomy and decompensated cirrhosis complicated by hepatic encephalopathy who
presented to the hospital with concern for altered mental status and was diagnosed with grade III
hepatic encephalopathy due to lactulose non adherence. During the hospitalization, patient
developed rectal bleeding with suspected colonic mass on imaging that was ultimately identified
as a large sigmoid gallstone ileus on endoscopic evaluation.

Conclusion
Our report aims to highlight the importance of considering gallstone ileus in the differential
diagnosis of colonic masses, especially in patients with relevant clinical history.