Hi Mom in Need,
I'm so sorry to hear of your daughter's retching problems. I had my Nissen 3 years ago, and haven't had those types of problems.
I have communicated with a mom with an 18mo old child who was very premature. This baby was tube fed for a long time was actually not interested in eating. He had a Nissen when he was an infant, as his LES was underdeveloped. He experienced lots of retching issues.
While I don't know if I have all these details exactly right, she has taken him to the Children's Hospital of Philadelphia and they have been treating him in some unique ways.
I think she said that some of the problem was due to a hypersensitive vagus nerve, and some other issues--I believe they were related to absorption. She has some very good docs working on her child's case.
Have you been able to visit a big medical center with a highly rated GI department? Since she's been dealing with this since she was a teenager, I wonder if you could seek help from a pediactric center...probably not, but just a thought.
The baby I mentioned has improved with treatment, and he is doing better. I wish I could provide more helpful information, but you post made me think of this case.
I wish you all the best in finding answers. I know it must be terrible watching your daughter suffer like that. Hopefully someone will be by soon who can offer more help.