They do the motility test to see if your swallowing reflex is normal and strong. In addition, they have to do it before the PH monitor, because it will give them the measurements they need to place the PH probe (unless you had an endoscopy and the doc had the foresight to write down the measurements).
I had it done, and while it's not like going on vacation, it's not all that horrible. You will see other posts that are very upsetting, but don't let them worry you. The most important thing is to work with your technician. You'll need to help swallow the tube, then once it's there, they''ll ask you to swallow a small amount of water on command.
You'll want to swallow in between, because of your natural inclination to swallow when you feel something in your stomach. If you can close your eyes and visualize a peaceful place, and do relaxation breathing--slowly in to the count of 4, and out to the count of four--it will make the whole process easier. There will be a technician to talk you through it, and if he/she is good it will help you relax.
They need to wait a certain amount of time between swallows, so your swallowing reflex can reset. They need recordings of clean swallows that will show your swallowing abilities. In addition the motility test can test the strength of your LES.
Good luck with all your tests! Relax and don't get yourself worked up and nervous about them. You'll get through them just fine.
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