This can be just from nausea which is also a common side effect from bariatric surgery. I get it a lot too. I was put on two nausea medications to control mine, it's been over a year and I'm still experiencing nausea and some dry heaving and vomiting. And many times that's on an empty stomach or with just liquids. So you're not alone. Supposedly removing my gallbladder was going to relieve the symptoms but it did nothing. Hope all is well!!