What could cause an indoor cat to have loose stool, she is having accidents everywhere. Do you think she has gotten in to milk, or does she need to see a vet?
You can probably give the cat a day or two before you worry. You should make sure the cat doesn't eat anything it shouldn't. If the cat isn't better in a day or two I would take her in.
Make sure she's drinking plenty of water. If it goes on too long she'll get dehydrated and the vet will want her on an IV. That's happened to my cat when she's been given too many treats behind my back by one of the nieces/nephews.
Are you giving the cat milk? I don't think milk alone would be the culprit. I would call the Vet and explain what is happening and ask what you should do. If it doesn't stop in a few days then I would think they would need to see the cat.