Reflux monitoring: role of combined multichannel intraluminal impedance and pH.

Combined multichannel intraluminal impedance and pH (MII-pH) is a promising technique that identifies liquid, gas, and mixed gastroesophageal reflux and categorizes it into acid and nonacid types. Gastroesophageal monitoring using combined MII-pH reconfirms previously reported data that there is a difference between refluxate volume presence time in the esophagus and time pH less than 4. Only one in five patients with persistent symptoms on acid-suppressive therapy have symptoms associated with persistent acid reflux, whereas two of five patients have symptoms associated with nonacid reflux; the remaining patients do not have any type of GER related to their symptoms. Combined MII-pH is a useful tool in evaluating patients with persistent symptoms on acid-suppressive therapy, patients with atypical symptoms, and infants.