Nausea after Nissen is not uncommon. I wrecked my wrap and reherniated from a short episode of vomiting.
My PCP gives me refills of Zofran. My GI doc says Nexium will cure the nausea. I take the Zofran when I need it, but if I feel a bout of constant pain from the stomach area (now mid-sternum after the surgery), I will take the Nexium for a couple of weeks or so.
I also have on hand at all times, including in my purse, some paregoric. It tastes incredibly bad, but a tablespoonful will stop vomiting even after it's started. The antinausea meds won't do that! Most docs don't know about
it because it's a really old med. It's cheap, keeps for years and years.