[Diagnosis using esophageal manometry and various loading tests]

Two approaches of infusion and microtransducer manipulation are available for esophageal manometry. If esophageal peristalsis and relaxation of the lower esophageal sphincter (LES) are diminished, the diagnosis of achalasia can be made. As compared with the infusion method, the microtransducer method requires no perfusion of water and has no limit on posture, allowing successful measurement in an empty esophagus. Thus this method, which allows measurement after feeding and continuous monitoring for 24 hours, seems to be more physiological than the infusion method. With this method, however, peristasis-like contractile waves and relaxation of the LES may be observed in addition to simultaneous contractile waves, even in cases of achalasia. Although methods to observe excessive reactions of the LES often involve a loading test with gastrin or mecolyl in some institutions, a loading test with cerulein is routinely used in our department. In healthy controls, administration of cerulein usually leads to decreased LES pressure, while increased LES pressure is observed in patients with achalasia (paradoxical response).