I had the sleeve in 2016 but had a stricture complication so in 2019 they converted me to a bypass in order to remove the stricture. This started continued nausea and vomiting. I now live on 8 mg Zofran tablets three times a day! My bariatric surgeon ran all the tests, checking stomach, intestines, gall bladder etc and told me that he believed it to be the part of the stomach they remove and leave in the body when they do the bypass. He explained that with the sleeve they actually remove the piece of stomach but with the bypass they leave the piece of stomach inside. He says that stomach piece should remain alive. Still producing bile and stomach acids etc just never being used any more to digest food. He mentioned if that stomach piece were to die that it will cause extreme nausea and vomiting! So he believes that is my issue. Only way to fix this is surgery to remove the piece of stomach. I still need to do the surgery but the Zofran is still doing its job so I haven't yet. I also am way under goal weight. Good luck to you!!! I hope you can find some relief soon! Please keep us posted!