Nissen Fundoplication is surgery done on both adults and children in an attempt to control acid reflux. The larger nodual of the stomach is wrapped around the esophagus and sewn together to create tension around the esophagus in hopes that this will keep the stomach contents and in some cases the acid that's refluxing up into the throat, down in the stomach. Patients are often back on PPIs in a year or have to tight of a wrap making it hard for food items to pass into the stomach from the esophagus.
The image here displays the before and after surgery.
Also something to consider is that a baby is in it's full developmental stage and everything about that baby is going to grow, including it's organs.
This can be horrifying to some moms, some that had just completed having the surgery on their children and some that were in line waiting for the surgery to be done. Most claimed that they tried everything and nothing worked including PPI therapy.
A couple of things that were found to be an issue in PPI treatment.