[Prevalence of different groups that comprise endoscopy-negative reflux disease].

Background Data: Endoscopic-negative reflux disease (ENRD) is a heterogeneous population. There are few data regarding the prevalenece of each group and subgroups that constitutes ENRD population.

Objective: To describe the prevalence of the differents groups and subgroups in ENRD.

Patients And Methods: We studied consecutive patients with frequent heartburn and acid regurgitation with endoscopically normal esophageal mucosa in whom ambulatory 24-h esophageal pH monitoring was performed. According with the pH-testing data and the correlation between symptoms and the acid reflux events, the subjects were classified in two groups: non-erosive gastroesophageal reflux disease (NERD) and functional heartburn. The functional heartburn group was splited in 3 subgroups: asymptomatics during pH-monitoring, hipersensitive esophagus and those with physiologic reflux with negative association between symptoms and acid reflux events. These last subgroup was classified in: minute changes of intra-esophegeal pH (upper than 4, n = 19) and non-acid related stimuli.

Results: One hundred and eleven patients with ENRD were classified in NERD (28%, n = 31) and functional heartburn (72%, n = 80). Patients with functional heartburn were classified in asymptomatics during pH-monitoring (11%, n = 12), hipersensitive esophagus (9%, n = 10) and those with physiologic reflux with negative association between symptoms and acid reflux events (52%, n = 58). In these last subgroup 19 (17%) patients were classified as minute changes of intra-esophegeal pH (upper than 4) and 39 (35%) as non-acid related stimuli.

Conclusions: Even most of the patients with ENRD have normal ambulatory pH-test, their symptoms are related with drops of esophageal pH in 26% of the cases. Eleven percent do not have symptoms during ambulatory pH-monitoring.