**Question:** Features of pyloric stenosis:

A. Inflammation
B. Dilation of the stomach
C. Shortened and hypertrophied pyloric muscle
D. Vomiting after feeding

**Core Concept:**
Pyloric stenosis is a congenital condition where the muscular ring at the pylorus, the narrowest part of the stomach, becomes narrowed and thickened due to hypertrophy of the smooth muscle cells, leading to impaired gastric emptying. This results in persistent vomiting after feeding, typically in infants.

**Why the Correct Answer is Right:**
C. Shortened and hypertrophied pyloric muscle (Option C) is the correct answer because it describes the key pathological feature of pyloric stenosis. The hypertrophied and shortened pyloric muscle leads to the narrowing of the pylorus, causing impaired gastric emptying and the characteristic symptoms seen in infants with pyloric stenosis.

**Why Each Wrong Option is Incorrect:**
A. Inflammation (Option A) is a possible cause of pyloric stenosis, but the correct answer focuses on the pathological feature of the condition.
B. Dilation of the stomach (Option B) is a common clinical finding but does not specifically address the underlying pathology of pyloric stenosis.
D. Vomiting after feeding (Option D) is a symptom of pyloric stenosis but does not directly describe the pathological feature of the condition.

**Clinical Pearl:**
Pyloric stenosis is typically seen in infants, usually presenting within the first three months of life. Prompt diagnosis and management are crucial as untreated pyloric stenosis can lead to malnutrition and dehydration. Treatment usually involves surgical intervention, known as a gastrojejunostomy, which involves creating an opening between the stomach and the small intestine to bypass the obstructed pylorus, allowing proper digestion and nutrition absorption.