[souffle]

You need to have her seen very soon. Is she still on any meds? It could be a reaction to the medication if so.
Is it definitely poo as sometimes a discharge from a womb infection can look like this. I don't think I'd risk trying to stress her with any bathing of the area until the vet has seen her. Is there any swelling of her tummy or leg at all. It could be that the leg limp is due to pressure of something wrong inside her tummy.
Keep her warm but not hot and offer food and water frequently. You may want to phone the vet and ask for advice? If there is any tissue hanging out her bottom then you must see a vet as this is very serious.
Sending healing vibes to her. x