In congenital hyperophic pyloric stenosis, the defect is in: (A) Nerve fibres, (B) Circular muscle fibres, (C) Longitudinal muscle fibres, (D) Mucosa
Answer is B. Infantile Hyperophic Pyloric stenosis In HPS, hyperophy of circular muscle of pylorus results in constriction & obstruction of gastric outlet Accquired condition Incidence of 1 in 3000 to 4000 live bihs This condition is most common between the ages of 3-6 weeks Associated anomalies in 6-20% cases : Esophageal atresia, Hirschprung's disease, ARM and malrotation Ref: Sabiston 20th edition Pgno : 1869