Today my cat began vomiting and passing clear mucus poop. A trip to the vet revealed a clear abdominal x-ray, no fever, no other signs of illness. Vet gave and antinausea shot and sent us home Science Diet Biome food. Kitty will not eat other than a few licks of the food (new or old). He has been sleeping mostly, but will purr and doesn't seem terribly unhappy. I am supposed to call the vet back tomorrow with a report. Any ideas of what this could be?