@tsch

No, I never utilied it, but if you look it up you will find all kinds of info about it and I doubt that all of it is lies. It's how the manipulation is done. If it was a simple tear they could go in and sew it back up, eh? FWIW the Nissen fundo can repair a hiatal hernia just like it can stop acid reflux due to a faulty pyloric valve.
https://www.google.com/search
""Yes, chiropractors can help with hiatal hernias using gentle adjustments and physical techniques, often providing relief for symptoms like acid reflux, heartburn, and chest pain by manually guiding the stomach back down through the diaphragm and addressing related nerve tension, though results vary and lifestyle changes (diet, posture, weight) are also crucial for long-term management, according to Horst Chiropractic and The Brost Clinic.""
https://accidentcarechiropractic.com/chiropractic-care-for-hiatal-hernias/
""A hiatal hernia develops when a part of your stomach bulges up through the muscle separating your abdomen from your diaphragm. The diaphragm features a small hole that allows food to pass through and move into the stomach. When someone has a hiatal hernia, the stomach passes into that hole.""

What you're calling a tear is probably the small hole that's already there.
In a Nissen fundo procedure the top of the stomach is brought up over the bottom of the esophagus similar to a turtleneck sweater. It is then sutured in order to keep it in place.

It's been at least 30-35 years since my Nissen fundo procedure and so far so good. After that I was looking at the chiro side and IIRC there were 2 chiro docs in the area that were listed as doing it.

One can be a doubting Thomas, but based on what I read here there are a lot of folks who end up with less than optimal outcomes from medical procedures. Seems like the smart ones might try the non-invasive option first. At the worst you end up unscathed. Of course with GERD you have a situation where the pyloric valve as been compromised and you end up with stomach acid where it shouldn't be.