JRP: My (almost) 3-year-old cat, Saima, USED to be an up-chucker when I first adopted her about a year and a half ago. She hasn't done it in over a year. I think in her case that when she used to up-chuck it was because she was over-excited and wolfed down her food too fast. Also, her main cat food is dry Iams (a very good, high-quality brand), which can be a little hard for her stomach to break down because the pieces are relatively big -- and Saima rarely took the time to chew (she does try to crunch up the pieces now, sometimes)! So, the food going into her tummy would fill up that space too fast (along with gulps of air?) and she would just chuck it right back up within the next few minutes. I did notice she would sort of cry(?) or make whimpering-type noises just before she would throw up, which could definitely signal discomfort! Otherwise this behavior didn't seem to really bother her. Saima never tried to re-eat it, but like your cat she would be back eating some more from her dish like nothing happened. I can't exactly say why my cat stopped up-chucking (so far so good, anyway), except that I think she naturally has calmed down a lot since I adopted her. Also, I tend to make sure there is always a little bit of food in her dish so that she's never in a raging hunger when I get home from work or when I get up in the morning. I hope your cat eventually stops up-chucking, but as "dogncatluvr" said, some cats may just always do this -- wow, for 13 years?! -- with no damaging effects to their health. Well, that's my experience. Hope it helps!