It is an investigation of motility function of esophagus and the LES (Muscular valve at the lower end of esophagus). A thin tube called catheter containing the transducer is inserted through the nose down your foodpipe. The catheter is attached to the manometry machine with sophisticated software. The catheter measures muscle contractions in different parts of the esophagus during the act of swallowing. Manometry reveals failure of the LES to relax with swallowing and lack of functional peristalsis in the smooth muscle of esophagus.