Thanks for the suggestions--I'm going to mention these to my vet. Charlie also has thickening of the bowels. We've done x-rays and an ultrasound so far, and nothing's shown up. However, one worry's off my mind--looks like my pet insurance covers a bit more than i thought it did, so at least the money worries are relieved. But, I'm still pretty worried that they're going to find out it's cancer.

Sick cat = much stress....