The classic endoscopic diagnosis of a Barrett's esophagus (BE) is based on the finding of greater than or equal to 3 cm, of distal esophagus covered by specialized columnar epithelium. However, currently, it is based on the finding of intestinal metaplasia (IM) at the squamous-columnar mucosal junction, independent of its extent. The aim of this study was to determine the prevalence of Barrett's esophagus by endoscopic and histological findings in control subjects and in patients with symptoms of gastroesophageal reflux (GER). Three hundred and six control subjects and 376 patients with symptoms of gastroesophageal reflux were included in this prospective study. Patients with Barrett's esophagus were classified in three groups as follows. 1. Intestinal metaplasia at the cardia. When endoscopy showed non-Barrett's esophagus, but histological intestinal metaplasia was found. 2. Short-segment Barrett's esophagus. When < 3 cm, was covered with tongues or finger-like or creeping substitution of distal esophagus. 3. Long-segment Barrett's esophagus. When > 3 cm, of distal esophagus was covered by specialized columnar epithelium. Two biopsies at the antrum, four biopsies at the squamous-columnar junction and one or two at the distal esophagus were taken. In control subjects, 1.6% showed histological IM at the esophagogastric junction. In patients with GER without esophagitis or with erosive esophagitis, IM was found in 18% and 10.7% respectively. 'Short-segment' Barrett's esophagus was three times more frequent than 'long-segment' Barrett's esophagus. Patients with Barrett's esophagus were significantly older than the other groups. The presence of complications or erosions, peptic ulcer or stricture were significantly more frequent among patients with 'long-segment' Barrett's esophagus (p < 0.0001). The prevalence of dysplasia was similar in all groups of patients with Barrett's esophagus. Complications such as ulcers, stricture and dysplasia were exclusively seen among patients with BE, whereas non-Barrett's patients did not exhibit these complications. In control subjects, IM can be found in a low percentage of cases. Among patients with symptoms of GER, the classic endoscopic diagnosis of a Barrett's esophagus can underestimate this condition in 80% of the cases. Patients with intestinal metaplasia at the cardia already present 17% of the cases with low-grade dysplasia. In all patients with symptoms of GER, systematic biopsies at the squamous-columnar junction should be taken.
