What is an esophageal pH test?
An esophageal pH test measures and records the pH in your esophagus to
determine if you have gastroesophageal reflux disease (GERD). The test can also
be done to determine the effectiveness of medications or surgical treatment for
GERD.
What is esophageal reflux?
Esophageal reflux is a condition in which stomach acid refluxes or moves
back into the esophagus (the "food pipe" leading from the mouth to the
stomach).
What happens during esophageal reflux?
A specialized muscle, called the lower esophageal sphincter, is located
where the esophagus meets the stomach (see figure). This sphincter opens to
allow flood and liquid to pass into the stomach, then closes. When the sphincter
does not close tightly, food particles, stomach acid and other digestive juices
can splash back up into the esophagus. When this happens, the condition is
called gastroesophageal reflux. When reflux occurs on a regular basis, it can
cause permanent damage to the esophagus. The esophageal pH test measures how
often stomach contents reflux into the lower esophagus and how much acid the
reflux contains.
How does the esophageal pH test work?
A thin, small tube with an acid sensing device on the tip is gently passed
through your nose, down the esophagus ("food tube"), and positioned
about 2 inches above the lower esophageal sphincter. The tube is secured to the
side of your face with clear tape. The end of the tube exiting from your nose is
attached to a portable recorder that is worn on your belt or over your shoulder.
The recorder has several buttons on it that you will press to mark certain
events. A nurse will review the monitoring instructions with you.
How do I prepare for the 24-hour esophageal pH test?
- Seven days before the monitoring period, do not take
proton pump inhibitors: Prilosec (omeprazole), Prevacid (lansoprazole),
Aciphex (rabeprazole), Protonix (pantoprazole), Nexium (esomeprazole)
- Two days (48 hours) before the monitoring period, do not
take the H2 blockers: Zantac (ranitidine), Tagamet (cimetidine), Pepcid (famotidine),
Axid (nizatidine); or the promotility drug, Reglan (metoclopramide)
- Six hours before the monitoring period, do not take
antacids (such as Alka-Seltzer, Gaviscon, Maalox, Milk of Magnesia, Mylanta,
Phillips, Riopan, Tums or any other brands)
- Four to 6 hours before your appointment do not eat or
drink
Please note: Occasionally, your doctor may want you to continue taking a
certain medication during the monitoring period to determine if it is effective.