Can a small hernia and/or diastasis recti cause constant nausea?

Had large tumor removed w/ vertical cut down entire midline from just under breastbone all way down past belly button. Felt fine after that. Constant nausea came after preg and C-section. Then had reflux surgery (lap Nissen), which barely helped. Nissen surgeon said I have a small hernia that didn't need fixing. Can small hernia and/or diastasis recti cause constant nausea? Anything else, anatomically, that could be out-of-whack? Could stomach be pushed out and not be in right position?