Heartburn, substernal discomfort, regurgitation, and chest pain are frequent complaints of patients under clinical evaluation (1, 2, 7, 9). Many times these symptoms are nonspecific, and radiological help is sought to distinguish their esophageal origin from cardiac or musculoskeletal disorders (3, 5, 11). In the past, this identification has often been difficult unless a scarred, deformed, and ulcerated esophagus demonstrated the end stage of chronic esophagitis or unless frequent episodes of free gastroesophageal reflux were observed during fluoroscopy (3, 5). One of the most crucial questions in this regard has been the clinical significance of a small sliding hiatus hernia or a lower esophageal ring detected radiologically (7, 9). Previous manometric studies have shown that acid perfusion of the esophagus induces abnormal esophageal motility in patients with clinical esophagitis (1, 2, 4, 8, 10). This information has been used to develop a simple effective method for the radiological diagnosis of peptic esophagitis. In addition to conventional barium suspension, patients receive acidified barium to study the effect of both mixtures on esophageal peristalsis. Experimental Method Twenty patients, 10 with symptoms of esophagitis and a positive acid perfusion test and 10 control subjects without esophageal symptoms and a negative acid perfusion test, were studied with simultaneous ciné manometric technic. Radiographically, the image was obtained with a kinescope, using 16 mm motion picture film. The intraluminal pressure was monitored by a four-channel direct-writing recording unit employing transducers and a train of catheters inserted into the body of the esophagus, with their tips spaced 5 cm apart. Conventional barium suspension as well as an acid-barium mixture were administered to each patient. The acid barium was made by mixing well 100 cc of standard barium sulfate suspension and 1 cc of concentrated hydrochloric acid (37 per cent), resulting in a pH of 1.7. The examination began with the patient in the prone right anterior oblique position, which permitted evaluation of the strength of peristalsis without the disturbing effect of gravity on swallowing. It is important to observe each progressive peristaltic contraction responding to a single barium swallow as it traverses the entire length of the esophagus, because subsequent swallows, if initiated prematurely, result in interruption of the peristaltic wave. Such interruption may be mistaken for segmental spasm. One or several swallows of conventional barium suspension were studied in this fashion fluoroscopically and recorded on 16 mm motion picture film. The same procedure was repeated with acid barium, with delay in ciné recording until two or three swallows had provided adequate contact of acid with esophageal mucosa.