Final answer:
The likely diagnosis for the 51-year-old man presenting with new onset jaundice, fever, and right upper quadrant pain and tenderness would be acute cholangitis.
Step-by-step explanation:
The 51-year-old man presented with new onset jaundice, fever, and right upper quadrant (RUQ) pain and tenderness. Based on the symptoms provided, the likely diagnosis would be acute cholangitis. Acute cholangitis is an infection of the bile ducts typically caused by an obstruction, such as gallstones. It is characterized by jaundice, fever, and abdominal pain. The next steps in the management of this patient would include obtaining blood cultures, initiating broad-spectrum antibiotics, and conducting imaging studies, such as an abdominal ultrasound or MRCP, to identify the source of the obstruction and determine the appropriate intervention.