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 a 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 aimed to highlight the importance of considering gallstone ileus in the differential diagnosis of colonic masses, especially in patients with relevant clinical history.