What is the following most characteristic feature of congenital hyperophic pyloric stenosis?
Diagnosis of congenital hyperophic pyloric stenosis can be made with a test feed, which produces a characteristic peristaltic wave which is seen to pass across the upper abdomen. Palpation of the abdomen at that time reveals the lump. Ref: Bailey and Love's Sho Practice of Surgery, 24th Edition, Page 1033.