I had surgery last Sunday (24/03) and had the same discomfort. I was in bits on Tuesday - had pains in my neck, jaw, shoulders, upper arms! I started to walk on the treadmill for 15 mins at a time 3 times a day and yesterday had a shower and went out for a walk. Feel so much better for it today.
During the surgery they pump in Co2 gas to gain access to your stomach and are unable to take it all out before being stitched up so, your body has to absorb/expel the gas over hte days following the surgery. best of luck