Sump syndrome (SS) is associated with choledocho-duodenostomy (CDD) dysfunction, which occurs due to accumulation of detritus, biliary mud and food remains in the suprapapillary distal common bile duct. The prevalence is low after CDD. Currently, biliary drainage endoscopic ultrasound (EUS)-guided with a lumen-apposing metal stent (LAMS) is a new minimally invasive alternative for biliary stenosis for patients in whom endoscopy retrograde cholangial-pancreatography (ERCP) is not feasible. CDD via EUS-guided LAMS is increasing. Thus, SS has become a potential associated complication that was previously unreported in the literature.