**Question:** A male child with gall bladder stone has Hb-6 gm%, serum bilirubin 2.5 mg % and high urobilinogen in urine. The diagnosis is -

A. Hepatitis
B. Jaundice
C. Choledocholithiasis
D. Acute appendicitis

**Core Concept:**

The clinical scenario presented involves a male child with a gall bladder stone, presenting with symptoms and laboratory findings typically seen in conditions affecting the liver and biliary tract. The core concept to understand here is the relationship between the liver, biliary tract, and the substances measured in this question: hemoglobin (Hb), serum bilirubin, and urobilinogen.

**Why the Correct Answer is Right:**

Correct answer C, Choledocholithiasis, refers to a blockage in the bile ducts due to gallstones, leading to jaundice. The presence of a gall bladder stone indicates a potential issue with bile flow, which is crucial in understanding choledocholithiasis. In this scenario, a high urobilinogen in urine signifies increased breakdown of red blood cells, possibly due to the blockage in the bile ducts caused by the gall stone.

**Why Each Wrong Option is Incorrect:**

A. Hepatitis (option A) typically presents with different symptoms, including fever, hepatomegaly, and elevated liver enzymes, which are not mentioned in this scenario.

B. Jaundice (option B) is a clinical sign of elevated bilirubin levels, but in this scenario, the serum bilirubin value is 2.5 mg%, which is not the highest value.

D. Acute appendicitis (option D) typically presents with right lower quadrant pain, peritonitis signs, and elevated white blood cell count. The provided scenario does not demonstrate these symptoms or signs.

**Clinical Pearl:**

Choledocholithiasis is a crucial differential diagnosis in patients with gall bladder stones, presenting with hepatobiliary symptoms and elevated urobilinogen. Understanding the pathophysiology of jaundice and the role of the liver, bile ducts, and gallbladder is essential for such scenarios. In the case of choledocholithiasis, the elevated urobilinogen level in urine is a result of increased breakdown of red blood cells due to impaired bile flow from the obstructed bile ducts. This is a critical point for medical students and residents to grasp, as it helps in formulating a proper differential diagnosis in clinical practice.