**Question:** Not true about congenital PUJ obstruction is

A. PUJ obstruction is always bilateral
B. The obstruction is caused by muscle spasm in the ureteropelvic junction
C. Symptoms are present in infancy and childhood
D. Treatment involves medication rather than surgery

**Correct Answer:**

**Core Concept:** Congenital PUJ obstruction (pyeloureteral junction obstruction) is a condition where the ureter meets the kidney at an angle that is too narrow for efficient urine flow, leading to impaired renal function.

**Why the Correct Answer is Right:**

Congenital PUJ obstruction is a developmental anomaly that affects the anatomy of the ureteropelvic junction. It does not involve muscle spasms (Option B) as the primary cause, but rather a structural abnormality. The obstruction is usually unilateral, though bilateral cases can occur.

**Why Each Wrong Option is Incorrect:**

A. PUJ obstruction is not always bilateral (Options A and D are incorrect). It can occur unilaterally as well, where only one kidney is affected.

B. PUJ obstruction is not caused by muscle spasms (Option B). It is primarily a structural abnormality, often due to a short or narrow ureteropelvic junction.

C. PUJ obstruction can present in infancy and childhood, but it can also manifest later in life (Options C and D are incorrect). Symptoms can vary and may not always be evident immediately after birth.

**Clinical Pearl:**

Congenital PUJ obstruction is a developmental anomaly that may present at any age. While the condition can cause symptoms in infancy and childhood, it is essential to consider this diagnosis in patients with renal dysfunction or hypertension later in life. A thorough history taking, physical examination, and imaging studies are crucial in making the correct diagnosis. Early diagnosis and intervention can prevent long-term complications and maintain renal function.