pH monitoring helps doctors link symptoms to acid surges, often before surgery or for tricky cases unresponsive to meds.

The patient’s nostrils are numbed using a cream or spray to make it easier for the gastroenterologist or a member of the team to pass a catheter through the patient’s nose and into the esophagus as they take sips of water. The tube is then taped to the patient’s nose to ensure that the catheter remains in place.

The procedure normally takes 15 to 30 minutes to complete. Once done, the patient is sent home and asked to wear a small data recorder on the belt for the next 24 hours. Patients can eat, drink and sleep as normal during this period, although they will need to keep a diary of their meals and activities and whether they experience any reflux episodes or symptoms. The doctor or a member of the team will remove the catheter, belt and data recorder the following day.