**Question:** Gallstones may be complicated by which among the following -

A. Choledocholithiasis (stone in the common bile duct)
B. Biliary colic (acute cholecystitis)
C. Acute cholecystitis (inflammation of the gallbladder)
D. Choledocholithiasis (stone in the common bile duct)

**Correct Answer:** **D. Choledocholithiasis (stone in the common bile duct)**

**Core Concept:** Gallstones are solid formations that can occur within the gallbladder or biliary tract due to the precipitation of bile constituents. They can lead to complications if they obstruct the biliary tract or cause inflammation.

**Why the Correct Answer is Right:** Choledocholithiasis, also known as stone in the common bile duct, occurs when gallstones enter the common bile duct during a gallbladder attack. This can lead to further complications due to obstruction of bile flow and activation of the local immune response.

**Why Each Wrong Option is Incorrect:**

A. Choledocholithiasis (stone in the common bile duct) is a separate complication, not a gallstone complication. Gallstones in the gallbladder remain within the gallbladder, not the common bile duct.

B. Biliary colic (acute cholecystitis) refers to the pain caused by gallstone obstruction, not a complication resulting from gallstones. Acute cholecystitis is an inflammation of the gallbladder, not a complication of gallstones.

C. Acute cholecystitis (inflammation of the gallbladder) is another complication of gallstones but is different from choledocholithiasis. Acute cholecystitis occurs in the gallbladder, while choledocholithiasis occurs in the common bile duct.

**Clinical Pearl:** Understanding the different complications of gallstones helps to diagnose and manage patients appropriately. If a patient presents with obstructive jaundice, choledocholithiasis should be suspected, while in patients with severe abdominal pain, acute cholecystitis should be considered. The correct diagnosis and management depend on the exact complication present.