There are no official guidelines to assist in answering this question. I will search for relevant research papers instead.
From the Research
Type of Emesis in Pyloric Stenosis
- The type of emesis that occurs in pyloric stenosis is nonbilious, projectile vomiting 1, 2, 3.
- This is a characteristic symptom of infantile hypertrophic pyloric stenosis (IHPS), which is the most common surgical cause of nonbilious, projectile vomiting in children 1.
- The emesis is typically nonbilious, meaning it does not contain bile, and is projectile, meaning it is forcefully ejected from the mouth 2, 3.
- In some cases, the vomiting may be accompanied by other symptoms such as a palpable pyloric tumor, visible gastric peristaltic waves, and hypochloremic, hypokalemic metabolic alkalosis 4.
- It is worth noting that while nonbilious, projectile vomiting is a classic symptom of pyloric stenosis, some patients may present with atypical symptoms, such as bilious vomiting or vomiting that is not projectile 5, 4.