Cholangitis and cholecystitis are intra-abdominal infections that show poor prognosis upon progression to sepsis and multiorgan failure. Administration of antibiotics with high antimicrobial susceptibility and removal of infected bile at the initial treatment are important. After undergoing ERCP for diagnostic purposes, a 58-year-old man developed acute cholangitis and cholecystitis accompanied by rhabdomyolysis, multi-organ failure, and severe sepsis. Broad-spectrum antibiotics with bedside endoscopic nasobiliary drainage were administered, but clinical symptoms did not improve. Therefore, bedside EUS-guided transgastric gallbladder aspiration and lavage was performed, resulting in successful treatment of the patient. We report the above described case along with a discussion of relevant literature.