<prompt> The metabolic derangement in congenital pyloric stenosis is:Hypochloremic alkalosisHyperchloremic alkalosisHyperchloremic acidosisHypochloremic acidosis  <response>: a. Hypochloremic alkalosisRef: Nelsons 20e p 1797-1799, Ghai 8e p 279-280High Yield Points:Congenital Hypertrophic Pyloric StenosisIt is the commonest surgical disorder of the stomach during infancyMore common in boys and in infants of blood group B and O; Usually does not present at birth, but after 3 weeks ageNon-billious vomiting is the initial symptoms of pyloric stenosis; leads to Hypochloremic metabolic alkalosis 