Back from the vet and fortunately all is okay (relatively speaking!). Inara does not have an obstruction, she just has an extremely irritated colon which is making her very lethargic and causing the bloody diarrhea. The vet gave her an injection to help with the irritation, and then pills for the next 2 days that will also help with the irritation. She said to give her some water with chicken broth in it but not to worry about food yet.
Poor Inara sooooo didn't feel well - she didn't jump on the vet and tech to say hello, she barely needed to be restrained, etc. She got lots of loving and sympathy there. And my grand total for her vet visit, rectal exam, injection and pills? $17. LOVE my vet.
Thank you all for the well-wishes - I was in a bit of a panic this morning. The vet said if she doesn't start perking up by tomorrow morning or if she vomits to take her back in but it looks like we should be good.