<prompt> GERD in the absence of endoscopic esophagitis is seen in:Paially treated cases with PPISclerodermaCRFCirrhosis  <response>: GERD is often diagnosed in the absence of endoscopic esophagitis. This phenomenon is seen in: Paially treated disease Abnormally sensitive esophageal mucosa. Next investigation in this setting would be: Reflux testing. It can demonstrate excessive esophageal exposure to refluxed gastric juice, the physiologic abnormality of GERD. Ambulatory 24- to 48-hour esophageal pH recording using either a wireless pH-sensitive transmitter that is anchored to the esophageal mucosa or with a transnasally positioned wire electrode with the tip stationed in the distal esophagus Ref: Harrison, E-18, P-2428 