(FA 2021, Pg. 369)

Patient has hypertrophic pyloric stenosis. This is the most common cause of gastric outlet obstruction in infant (1:600).

Clinical features:

• Palpable olive-shaped mass in the epigastric region
• Visible peristaltic waves
• Non-bilious projectile vomiting (make sure you can differentiate this with intestinal atresia which presents with bilious vomiting)
• Appears around 2-6 of age
• More common in first born males
• Associated with macrolide exposure

Imaging (ultrasound): Will demonstrate a thickened and lengthened pylorus

Treatment: Surgical incision of the pyloric muscles (pyloromyotomy)