**Core Concept:** Abdominal X-ray findings in neonates with intestinal obstruction and constipation. Multiple air-fluid levels indicate a mechanical obstruction, while levels of air alone suggest a dilated bowel loop.

**Why the Correct Answer is Right:** In the context of a neonate presenting with intestinal obstruction and constipation, the presence of air-fluid levels on abdominal X-ray indicates a mechanical obstruction. This is due to the constipation and subsequent dilation of bowel loops, causing the air-fluid levels.

**Why Each Wrong Option is Incorrect:**

A. Flat bowel loops: This is incorrect because the air-fluid levels are present, suggesting mechanical obstruction rather than a dilated bowel loop without air.
B. Single air level: This is incorrect because the presence of multiple air fluid levels indicates a mechanical obstruction, not just dilation of a single bowel loop with air.
C. Normal bowel loops: This is incorrect because the neonate is presenting with symptoms of obstruction and constipation, and the X-ray findings support a mechanical obstruction.
D. Air-fluid level with no constipation: This is incorrect because constipation is a key symptom in this scenario, suggesting a mechanical obstruction rather than a simple dilation of bowel loops.

**Clinical Pearl / High-Yield Fact:** In neonates, constipation and air-fluid levels on abdominal X-ray point towards a mechanical obstruction, which should prompt further investigation and management for this potentially life-threatening condition.