Has anyone had this problem?

I had my surgery 4 weeks ago, and was doing well at first. However,
for the past 1 1/2 to 2 weeks, I'm having alot of trouble keeping my
food down. I get a pain in my chest when I eat, then must vomit,
during which time I vomit a large amount of clear mucous. It
doesn't seem to matter what I eat; eating sugar-free pudding was
going pretty well, but today I vomited that. However, I had mashed
potatoes and roast (which I sliced really, really thin) for dinner
tonight, and that stayed put. Earlier this week I had an upper GI
done, an obstruction x-ray study and lab work done, and I'll be
seeing my surgeon on Monday to try to get to the bottom of this.
Anyone else have any experience with this? Thanks, laci