[Prevalence of different groups that comprise endoscopy-negative reflux disease]. / La prevalencia de los diferentes grupos que integran la enfermedad por reflujo con endoscopia negativa.

ABSTRACT

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.