The columnar lined (Barrett's) esophagus is an acquired condition resulting from chronic gastroesophageal reflux. The clinical spectrum of 50 consecutive cases of endoscopically consistent, histologically proven Barrett's esophagus was reviewed. The mean age of patients was 65.9 +/- 12.4 (SD) years with only four patients younger than 50 years. The predominant presenting symptoms were dysphagia, heartburn, and regurgitation. At endoscopy, the columnar lined segment extended over 6.5 +/- 3.0 cm of the lower esophagus. Specialised columnar (intestinal) epithelium was the most frequent histological type identified. Radiologic or endoscopic evidence of a hiatal hernia was present in the majority. Complications were present at endoscopy in 38 (76%) patients. Reflux esophagitis (56%) was present at the area of the squamo-columnar junction. Stricture formation (38%) and ulceration (36%) were located either at the squamo-columnar junction or more distally within the columnar epithelium. Two patients (4%) had adenocarcinoma arising in a segment of Barrett's esophagus at presentation. Treatment included physical measures, dilatation, and cimetidine. Bougienage in 20 patients was successful in alleviating dysphagia but multiple treatment sessions were often necessary. Although esophagitis readily resolved with cimetidine therapy, ulceration was generally resistant to medical therapy. Indeed, by two months, healing was achieved in only five of 12 patients. Endoscopic surveillance of 12 patients who received cimetidine (1 g/day) for at least 12 months showed no regression of the metaplastic mucosa.