Poor Bella!! - I feel you lady, Ellie has had the poopies a couple times, and the same very situation you had, Ellie had ONLY been in her crate just a couple hours while we went to visit family, Since I'm still quite the new bully mommy, I am not an expert, but I would definitely get a sample to the Vet ASAP & also give them a call and see what they advise on feeding her. They may suggest a bland diet, or fasting for a short amount of time.
Good Luck, Keep us Posted!!