Emperor

I am now postoperative day 4 and I am struggling to tolerate anything. When I drink anything, I get very intense pain in the midepigastric region, upper abdomen, and up towards my chest on the left side. It feels like my stomach is full of gas. It's severe enough it makes me stop drinking. This happens with Protein shakes, Water, and everything else. It sometimes occurs with as little as my 15mL of pain medicine. It is intense for ~10 minutes, then begins to decrease over the next 30mins. I had the VSG and hiatal hernia repair. Is this common? I'm worried I am getting dehydrated as its impossible for me to get in my recommended fluids.