## **Core Concept**
The clinical presentation described for the 2-hour-old male infant, including vomiting of stomach contents and bile, abdominal distension, and inability to pass meconium, is suggestive of **intestinal obstruction**. This condition can be caused by various factors, including mechanical obstructions such as **intestinal atresia** or **pyloric stenosis**, but the specific constellation of symptoms points towards a more distal obstruction.

## **Why the Correct Answer is Right**
The symptoms described—vomiting bile, abdominal distension, and failure to pass meconium within the first 48 hours of life—are classic for **duodenal atresia** or **jejunal atresia**, conditions that represent a complete obstruction of the small intestine. **Duodenal atresia** is characterized by the "double bubble" sign on abdominal X-ray, indicating obstruction at the level of the duodenum. The condition results from a failure of the intestinal lumen to recanalize during embryonic development. The presence of bile in the vomit indicates that the obstruction is distal to the ampulla of Vater, making **duodenal atresia** a likely cause.

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is not provided, but typically, conditions like **pyloric stenosis** would present with non-bilious vomiting and are less likely to cause failure to pass meconium.
- **Option B:** Similarly, not provided, but conditions such as **gastroesophageal reflux** would not cause failure to pass meconium or abdominal distension to this extent.
- **Option C:** Without specifics, it's hard to address directly, but any condition not leading to a mechanical obstruction or significant dysmotility would not explain the full spectrum of symptoms.
- **Option D:** Assuming this is not the correct answer, any condition not directly causing mechanical obstruction of the intestines would not fully explain the clinical picture.

## **Clinical Pearl / High-Yield Fact**
A key clinical pearl is that **failure to pass meconium within the first 48 hours of life** is highly suggestive of intestinal obstruction. The "double bubble" sign on abdominal X-ray is pathognomonic for **duodenal atresia**. Early recognition and surgical intervention are critical for a favorable outcome.

## **Correct Answer:** D. Duodenal atresia.