Dual Bowel Obstruction: A Rare Case of Gallstone Ileus and Colonic Adenocarcinoma.

Bowel obstruction is a surgical emergency that leads to a high rate of admissions. Twenty percent of patients with acute abdominal pain will be diagnosed with bowel obstruction; eighty percent of them are of small origin. It is classified based on etiology to either mechanical or functional. Mechanical obstruction is a physical barrier that obstructs the passage of bowel content; it could be caused by adhesion, tumors, volvulus, hernias, strictures, and gallstone ileus. Functional obstruction is usually due to impaired peristalsis or metabolic disorders. In this article, we report a case of an 80-year-old gentleman with no previous surgical history who was found to have a bowel obstruction. Diagnostic imaging and colonoscopy showed that his clinical presentation was due to gallstone ileus with cholecysto-enteric fistula and sigmoid mass. He underwent exploratory laparotomy with small bowel resection and sigmoidectomy with primary anastomosis and diverting ileostomy. The final pathology showed early moderately differentiated polyp adenocarcinoma T1N0 and was kept on surveillance. The novelty of this case is the presentation of two different abdominal pathologies, which lead to large and small bowel obstruction. Thus, the management decision was challenging, and a thorough workup is advisable in such cases.