A 6-year-old boy presenting with a palpable abdominal mass in the epigastrium. The clinical diagnosis is (There is no bile in vomitus) –
Diagnosis of congenital hypertrophic pyloric stenosis 

History of vomiting without bile (nonbilious vomiting).
Physical examination -


Palpable mass in the epigastrium
After feeding, visible gastric peristaltic wave those progress across the abdomen.

USG confirm the diagnosis

Criteria → Pyloric thickness > 4 mm or an overall pyloric length > 14 mm.

Contrast studies -

Shoulder sign → A bulge of the pyloric muscle into the antrum.
Double tract sign → Parallel streaks of barium in the narrowed channel.
Elongated pyloric channel


So the boy is having pyloric stenosis. The only problem is the age of boy i.e 6 yrs. The hypertrophic pyloric stenosis which we know of makes its clinical presentation in early infancy (3rd to 6th weeks of life)
But the problem is solved once you know that there is a similar disease in adults - hypertrophic pyloric stenosis of adults. (Bailey & Love, 22th/e, p 675).
Duodenal Atresia
Choledochal cyst
Pyloric stenosis
Oesophageal Atresia