A case of migrated plastic biliary stent in the CBD previously for Choledocholithiasis resulting in sigmoid colon perforation. ERCP has vital role in the diagnosis and management of various biliary and pancreatic diseases but is also associated with adverse events. Reported complications are pancreatitis, cholangitis, bleeding, cholecystitis, post sphincterotomy strictures and perforation. Migration of stents, which is more with plastic stents, is a well known complication of ERCP. A 95 year old woman was admitted to the emergency department with sudden onset of worsening abdominal pain and abdominal distension. She had a history of choledocholithiasis treated with ERCP and biliary stenting in the common bile duct 8 months ago. On physical exam, abdomen was soft, and nondistended, hypoactive bowel sounds, marked left quadrant tenderness and rebound tenderness. Her initial vital signs were normal,patient was stable and a normal CBC. Her CRP was elevated at 6.8. Her CT scans were significant for free air, extensive diverticulosis of the colon, and a biliary stent in the sigmoid colon, suspicious for a diverticular perforation caused by the stent. The decision was made to treat her conservatively. Her abdominal pain improved gradually, however her abdominal distension has worsened and her blood work was significant for leukocytosis. Repeat CT scan of the abdomen after 3 days showed significant progression with marked fluid collection, extensive inflammatory changes, and increase in the free air .Conservative treatment has failed with significant collection in abdomen as noted by a CT scan. So, she had exploratory laparotomy, sigmoid colon resection with splenic flexure release, end colostomy with evacuation of pelvic abscess. The patient tolerated the procedure and returned to the recovery room in stable condition. After an uncomplicated recovery period, the patient was discharged. Biliary stents are used for treatment of obstructive jaundice from either benign or malignant causes. Indications: Primary pancreaticobiliary malignancy, Metastatic disease and External biliary complications. Types of stents: Plastic and Metallic, Migration: Common site: Duodenum, Rare: Colon, Complications: Most common: Stent occlusion and Stent migration, Less common: Cholecystitis, Cholangitis, Pancreatitis, Perforation and Bleeding, Intervention: Endocscopic retrieval, Surgery rarely necessary.1258_A.tif Figure 1: ERCP image showing a plastic biliary stent placed in the common bile duct1258_B.tif Figure 2: CT image showing biliary stent in the sigmoid colon1258_C.tif Figure 3: CT image showing biliary stent in the sigmoid colon