Patient instructions for 24-hour pH study

You are scheduled for a 24-hour pH study. This is a test to evaluate gastroesophageal reflux. Heartburn, chest pain and indigestion are symptoms of gastroensophageal reflux disease (GERD). Reflux occurs when the contents in the stomach regurgitate back into the esophagus. Your doctor may want to evaluate you for GERD before or after prescribing medication or performing surgery to relieve GERD.

A small catheter (pH catheter) will be passed through one side of your nose. The catheter will be advanced into the esophagus. The catheter will remain in place for 24 hours. The catheter will be attached to a small recording device which may be secured around the waist or over the shoulder.

Please arrive 30 minutes prior to your appointment for registration. If you are unable to keep your appointment, you must cancel at least 48 hours in advance or you will be referred back to your primary care physician.


For adults:

  • Wear loose comfortable clothing that buttons up in front.
  • Do not eat or drink anything six hours before pH catheter placement.
  • No proton pump inhibitors for at least seven days (e.g. Prevacid, Prilosec, Aciphex, Nexium, Protonix)
  • No H-2 blockers for 48 hours (Axid, Pepcid, Tagment, Cimetideine, Zantac).
  • No antacids 24 hours before catheter placement (Maalox, Mylanta, Tums, Gaviscon)
  • No x-rays while the catheter is in place.
  • You may not shower or tub bathe while catheter is in place. Sponge bathe only.
  • Do not operate a microwave while probe is in place.

If esophageal pH study is being performed to test effectiveness of medicine, the patient should continue their normal medcation.

If you have any questions or concerns, please call the Gastroenterology Unit, Monday through Friday, 6:30 a.m. - 4 p.m. at 916-734-5561.