**Question:** Double-bubble sign in X-ray is seen in

A. Colonic obstruction
B. Hiatal hernia
C. Diverticular disease
D. Inguinal hernia

**Correct Answer:** C. Diverticular disease

**Core Concept:** The double-bubble sign is a radiological finding in abdominal X-rays that is indicative of specific pathologies affecting the gastrointestinal tract. These pathologies cause distention of the small bowel and the colon, leading to the characteristic appearance on X-ray.

**Why the Correct Answer is Right:** The double-bubble sign is primarily seen in conditions involving the colon and rectum, which are responsible for the two bubbles in the sign. In diverticular disease, tiny pouches called diverticula develop on the outer layer of the colon, causing distention and the radiological appearance of the double-bubble sign.

**Why Each Wrong Option is Incorrect:**

A. Colonic obstruction (A) is characterized by a single, dilated bowel loop, not the double-bubble pattern.
B. Hiatal hernia (B) typically presents with signs like gastric bubble and mediastinal shift, not the double-bubble sign.
D. Inguinal hernia (D) is a condition involving the groin region and does not demonstrate the double-bubble sign.

**Why the Correct Answer is Right:** The correct answer, diverticular disease (C), is associated with the double-bubble sign due to the presence of diverticula in the colon causing dilated bowel loops, which results in the characteristic appearance on X-ray.

**Clinical Pearl:** The double-bubble sign is often used as a diagnostic clue for diverticular disease on abdominal X-ray, adding to clinical suspicion and guiding further evaluation or intervention. It is important for radiologists and physicians to be familiar with this sign, as it can help diagnose and manage patients with diverticular disease effectively.