Did it just start? After my Nissen, I had trouble with what seemed like tons and tons of saliva...I spit it out because there was so much. I just looked on the Mayo Clinic site and it says that it might be that you're just not swallowing as much. I think that was the case for me. I didn't want to swallow that much after my surgery.
Here's the URL, in case you haven't seen it:
I hope you find an answer soon! Until then, keep swallowing!