pH Manometry

Prior to my first fundoplication, I underwent a 24 hour pH manometry to assess how often and how much I refluxed acid.

This provided a DeMeester score of 179 when anything over 14.7 indicates excessive acid reflux.

In October 2025, I underwent another.

Swallowing difficulties and aspiration

In the summer of 2024 I started developing swallowing problems causing me reflux symptoms which I knew weren't gastric in origin.

With my next surveillance scope due, I waited to see what it would reveal.

I told Jun, the endoscopist and she said she'd take a partiuclar look at the cricopharyngeus. However, she found she could not get me to swallow the scope. After a few minutes she tried again successfully. My Nissen wrap is holding fine - I saw the twist of the ruggae on the patient screen as the sope was retroflexed in the stomach.

She arranged for me to have a Barium Swallow which revealed a Cricopharybgeal Dysfunction which was then sorted with a CricoPharyngeal Dilatation using a bougie cap. Knowng it would be painful, and that normal sedation doesn't work for me, they made a mixture of two sedatives which worked like a dream.

It cured the probem, partly, though I still had a cough and difficulty swallowing, so I was lined up for an ENT apointment and anoter 24hr manometry.

ENT were happy I'm learning to manage it and that gastro can provide a CP dilation again if/when needed.

The 24hr manometry, however, made me feel like a fraud. During the monitoring period, I didn't really experience any reflux or swallowing issues to talk about which made me wonder if the probe could actually affect the result.

Does the 24hr manometry probe affect sphincter function and motility?

Personal observation.

A dysfunctional cricopharyngeus (Upper Oesophageal Sphincter) has been causing me some swallowing issues resulting in aspiration causing coughing whilst at the same time, I have experienced poor motility.

As part of the investigations, I recently undertook a 24hr pH manometry test whereby a pH probe is placed through the oesophagus and reflux episodes recorded over 24 hours.

Surprisingly, during those 24 hours, I experienced far fewer episodes than normal, and at far less magnitude.

The scientist in me always asks “Why?” when an anomaly is observed.

Does the existence of the probe affect the readings?

Hypotheses

1. The presence of the probe passing through the sphincter may help it open to the oeosphagus.

2. The Coanda effect may cause tracking of liquids along the probe into and through the oesophagus.

I devised an experiment to test my hypotheses.

The apparatus requires two tubes to represent the trachea and the oesophagus, leading to two receptacles representing the lungs and the stomach.

A cellophane membrane stretched over the openings of the two tubes bearing a small slit, represents the sphincter.

1. Some water is dripped onto the cellophane membrane sphincter.

2. The probe is placed through the slit in the membrane and fed down the oesophagus before the water drip test is repeated.

Results

Initially water ended up in both the “lungs” container and the “stomach” container.

With the probe in situ, nearly all of the liquid ended up in the “stomach” container.

Comment

The actual apparatus u tilised a piece of plastic piping, a piece of bicycle inner tube, two dishes, some parcel tape for the membrane, with a clit cut in it, and the manometry probe that had been used in my recent test.

Of course, to provide a meaningful experiment, the apparatus could be refashioned and I failed to measure the amounts of water delivers and collected in the respective vessels but this exercise did appear to prove my hypotheses.