<prompt> A 4-week old first-born, pre-term boy admitted to your dept. 3 days ago. Chief complaint was Vomiting which was projectile without bile in it, and follows each feeding, and the baby is hungry and eager to eat again after he vomits. The baby is dehydrated and has visible gastric peristaltic waves and a palpable Olive sized mass in the RUQ. What is the surgery of choice?DuodenostomyBillroth Type-I GJstomyKASAI operationRamstedts pyloromyotomy  <response>: CHPS: Congenital Hyperophic Pyloric Stenosis IHPS: Infantile Hyperophic Pyloric Stenosis Clinical features After breast feeding, breast milk accumulates in stomach. Obstruction due to hyperophy at pylorus causes multiple episodes of non-bilious vomiting which can be projectilenon-projectile. IOC for diagnosis - Ultrasound Management Resuscitation by I.V fluids correction of Dyselectrolytemia Fluid of choice- Normal Saline Treatment of choice after resuscitation 