<prompt> 24 hour pH manometery is gold standard investigation for?Hiatal herniaBarretts esophagusReflux esophagitisEsophageal ulcers  <response>: ANSWER: C Reflux esophagitisREF: Sabiston 18th ed p. 1112The gold standard for diagnosing and quantifying acid reflux is 24 hour pH test, and 24 hours pH score is DeMeester score 