Can weight gain after tummy tuck cause abdominal pain?

My surgery was March 2016. Just before my one year post-op visit I started getting pain in my abdomen (nothing to do with the incision, the pain is much higher). At that point I had gained about 10lbs since the surgery. Since then, however, I've probably put on an additional 5-10lbs. I feel more of a pressure than pain, but it's extremely uncomfortable. Sometimes I feel like there's a knot in my stomach. I'm going for an endoscopy next week to see if there are any other issues. Any thoughts?