This trial was designed to assess the prevalence and characteristics of 
Jackhammer esophagus (JE), a novel hypercontractile disorder associated with 
progression to achalasia and limited outcomes following anti-reflux surgery in 
patients with typical symptoms of GERD and responsiveness to proton pump 
inhibitor (PPI) therapy. Consecutive patients, who were referred for surgical 
therapy because of PPI responsive typical symptoms of GERD, were prospectively 
assessed between January 2014 and May 2017. Patients diagnosed with JE 
subsequently underwent rigorous clinical screening including 
esophagogastroduodenoscopy (EGD), ambulatory pH impedance monitoring off PPI and 
a PPI trial. Out of 2443 evaluated patients, 37 (1.5%) subjects with a median 
age of 56.3 (51.6; 65) years were diagnosed with JE and left for final analysis. 
Extensive testing resulted in 16 (43.2%) GERD positive patients and 5 (13.9%) 
participants were observed to have an acid hypersensitive esophagus. There were 
no clinical parameters that differentiated phenotypes of JE. The prevalence of 
JE in patients with typical symptoms of GERD and response to PPI therapy is low. 
True GERD was diagnosed in less than half of this selected cohort, indicating 
the need for objective testing to stratify phenotypes of JE. (NCT03347903).