Which condition is associated with paradoxical aciduria and non-bilious vomiting?

The condition associated with paradoxical aciduria and non-bilious vomiting is congenital hypertrophic pyloric stenosis (CHPS). In CHPS, the hypertrophy of the pylorus leads to gastric outlet obstruction. This obstruction causes the stomach to distend and results in non-bilious vomiting, as the vomit consists solely of the contents of the stomach and does not contain bile due to the obstruction occurring above the entry point of bile from the duodenum.

Paradoxical aciduria occurs because the body's ability to excrete hydrogen ions (H+) through urine is impaired in the setting of metabolic alkalosis, which can develop due to the loss of hydrochloric acid (HCl) from repeated vomiting. As the body becomes more alkaline, the kidneys may excrete bicarbonate (HCO3-) instead of hydrogen ions, leading to paradoxically acidic urine. This physiological response is unique to conditions where there’s significant vomiting, particularly when the vomiting is associated with gastric outlet obstruction like in CHPS.

In contrast, intussusception is characterized by abdominal pain and the presence of "currant jelly" stools, primarily because it leads to bowel obstruction as well but does not commonly present with paradoxical aciduria. Pyloric stenosis