Which of the following condition is associated with Paradoxical aciduria?

Paradoxical aciduria refers to passage of acidic urine even though patient is alkalotic. It is usually seen in patients with severe gastric outlet obstruction. Patients with gastric outlet obstruction suffer from severe nausea and vomiting, and loss of acid and chloride ions which result in hypochloremic alkalosis. Because of severe sodium depletion in these patients, distal renal tubules secrete potassium and hydrogen ions in exchange for sodium in glomerular filtrate. Urine therefore becomes acidic even though the patient is alkalotic. Ref: Textbook of Surgery edited by Joe Tjandra, 3rd edn, Page 99