Veterinary questions? Ask a Vet for Answers ASAP
Hi, Welcome to Just Answer. I'm Chris, a small animal Vet based in the UK. I am reviewing your question and will get back to you as soon as possible
Sorry to hear that she has been unwell. Has she has diarrhoea in addition to passing this material? How does she seem in herself?
Ok, if she seems bright in herself and is not having active vomiting or diarrhoea right now then I think she will be ok until your appointment tomorrow. The material she passed does look quite concerning for some large intestinal lining suggesting quite bad colitis - this may need investigations/treatment tomorrow.
I hope that answers your question, please let me know if you need any further help or advice.
It is not possible that she would have pooed out stitches from the spaying, that must be something that she has eaten at some point. Indeed what you are seeing could in fact be material she had ingested and not bowel lining at all - if you take it to the vets they will be able to check.