A 6wk child is brought in with vomiting, constipation and decreased serum K+. What is the dx?
a. Pyloric stenosis
b. Duodenal atresia
c. Hirschsprung disease
d. Achalasia cardia
e. Tracheo-esophageal fistula
Ans. The key is A. Pyloric stenosis. [why not duodenal atresia? Pyloric stenosis is much more commoner
than duodenal atresia; in duodenal atresia the vomitus should contain bile, which is not the case in
pyloric stenosis].