Certified Pediatric Nurse (CPN)

Which statement is true regarding the vomiting pattern in pyloric stenosis?

1. Vomiting is typically bilious from the onset

2. Projectile vomiting occurs as the pyloric muscle thickens

3. Vomiting consistently decreases in frequency

4. Vomiting is usually associated with fever

The correct answer is: Projectile vomiting occurs as the pyloric muscle thickens

In pyloric stenosis, the correct assertion is that projectile vomiting occurs as the pyloric muscle thickens. This condition is characterized by a narrowing of the pylorus, which is the opening from the stomach into the small intestine. As the muscles of the pylorus become increasingly hypertrophied, they obstruct the passage of food, leading to a forceful ejection of stomach contents, which is described as projectile vomiting. This type of vomiting is often observable even after the ingestion of small amounts of food. Other statements do not accurately reflect the typical clinical presentation of pyloric stenosis. For instance, vomiting in this condition is not typically bilious at onset; it is often non-bilious and consists primarily of undigested food. Additionally, the frequency of vomiting tends to increase rather than decrease, particularly as the stenosis worsens. Lastly, vomiting is generally not associated with fever unless there is another underlying condition or complication, such as infection.