I've just recently gone through something very similar with my Halo....started with vomitting, but no diarreah. Then she wouldn't take food at all. I was feeding and giving her water with a syringe. The vet tried different meds and also gave her fluids under the skin. X-rays showed no blockage. Finally, I discovered a tick
embedded in her skin. It was so red around it. The vet got the tick out and changed her meds to doxycycline and a low dose cortizone. It's been about 3 days now and she's so much better. But, she hasn't had a BM
Vet also did an enema last Wed. She really just started eating again over the weekend. I'm giving her pumpkin, so if there's nothing today, back to the vet we'll go.
Anyway, I said all this to say inspect her for ticks! Hope she's better real soon.