No, the surgery doesn't do a thing for the acid. All it does is keep it in the stomach where it belongs. People with typical reflux issues (a little heartburn here and there...within "normal" limits) have that same acid in their stomachs. It's normal (aside from things like Zollinger-Ellison Syndrome that increase the amount of acid) to have acid. It just doesn't cause them problems like it does us.
That's why people like me, who've had the surgery but have reactive stomachs with frequent gastritis issues, continue to take PPIs after surgery. With gastritis it's important to keep the acid down so the stomach lining can heal. Stress also continues to increase acid production. The surgery only helps keep the acid in the stomach, rather than refluxing up the esophagus, which is not equipped to handle acid.
The reason people don't use PPIs after surgery is because the acid is kept in the stomach, where it belongs. The stomach lining is generally well-equipped to handle that acid. It's the tissue of the esophagus that can't handle the acid.
There is no guarantee that after the surgery you'll never need PPIs again. It's pretty common for post-Nissen patients to need some PPIs--usually at a lower level. I think those with LPR symptoms might be more likely to need some level of PPI even after the surgery. That's because they are much more reactive to even small (normal) amounts of acid.
People who have typical GERD aren't as likely to need PPIs post-surgery because their reflux issues are different. They're generally refluxing large amounts of acid and even food into their esophagus and mouth. They're not generally reactive to a little reflux that might occur after surgery. They can have the surgery and go off PPIs pretty much immediately.
LPR patients, though, could get some symptoms with tiny amounts of reflux. The thing is, the surgery can't be made tight enough to guarantee that every bit of acid stays in the stomach. That would make it impossible to swallow food. Surgeons are going for "normal" amounts of reflux--the type that doesn't cause damage or create pain and suffering.
Everybody out there who is eating GERD triggers at will with no problems have some reflux. They may pop a Tum here and there, or even take Maalox after a party. Still, their small amount of reflux is not causing them any trouble.
I had the surgery for LPR symptoms...especially severe asthma. The surgery has improved my lungs 100% (I still have allergy induced asthma, so they're up and down during the pollen season). I still take PPIs to keep my gastritis symptoms in control. That said, my asthma doc and PCP both like me on one dose of 40mg Protonix before dinner because my lungs are so reactive they don't want to risk even a touch of acid getting to them. I also continue to sleep with the head of my bed elevated. Better to be safe than sorry!
I'm not all that disappointed that I'm still on PPIs for my condition. Before surgery I was on 80mg Protonix a day, as well as 300mg Zantac at bedtime, and STILL my lungs were dangerously inflamed. My doctor really pushed me toward surgery because, as he said, it was a life-threatening condition. I'm just happy to have healthy lungs again. That's why I had the surgery in the first place. Would I like to be PPI free? Sure! But the surgery has allowed me to reduce my steroid dosage tremendously. I just take a small maintainance dose, rather than the unhealthy dose I had to take prior to surgery.
So that's my take on your simple question!
Have a great day.