<prompt> 3 month infants with abdominal palpable mass non bilious vomiting -Hypertrophic biliary stenosisHypertrophic pyloric stenosisTracheoesophageal fistulaDuodenal atresia  <response>: Ans. is b i.e., Hypertrophic pyloric stenosis Hypertophic pyloric stenosiso Most common cause of nonbilious vomiting is Hypertrophic pyloric stenosis,o Male female.o Vomiting starts with 3 week of age.o Palpable mass is seen in epigastric region,o Visible peristalsis is seen soon after feeding,o Confirmed by USG abdomen,o Contrast study shows :Shoulder signDouble tract sign.o Treatment surgery Ramstedt procedure. 