New mum with chronic diarrhoea

Hi everyone, i am a fosterer for Cats Protection.
I rescued a mum with 3 6 day old kittens last night and she has chronic diarrhoea!
Everywhere but in the litter tray lol.
She ate when i brought her in last night but has not eaten since.
Took her to the vets today but he didnt want to treat her as she is feeding younguns and has given me fortiflora (probiotics) for her.
She came from a home with 15+ cats, the owner had been evicted and cats left behind. Any advice very much appreciated! :-)

What is she eating?

she had some whiskas last night, and i gave her some today but she hsnt eaten it, she has a bowl of dry food in too

Did your vet do a fecal on the cat? If so, what did it show? Has she been dewormed? Strongid can safetly be used in nursing cats. I would guess that the environment she came from was not the cleanest so it's quite possible that she has something like giardia or coccidia which can cause diarrhea. Nursing mothers can be treated with some drugs. Most antibiotics are okay. Drugs like Amoxicillin and Clavamox can be used in nursing mothers and small kittens. Although it's not an ideal treatment for diarrhea it can help in my experience.

It's very important that your mom cat eats and drinks. A cat's body can shut down if they go without food for even a pretty short time. She also needs nutrients to be able to provide her kittens with what they need. If she's not eating what you are giving her try something else. Fish flavored Fancy Feast are usually a big hit. You can also "force feed" her kitten formula and nutrical by using a syringe or stickin the nutrical up on the roof of her mouth. If she doesn't start eating soon she has to go back to the vet.

Was she eating Whiskas at her previous home? A change in diet can upset tummies, and Whiskas can be pretty rough on many cats.

I would switch her to boiled chicken for a couple of days to help settle her. Iams Hairball is also good to settle tummies.

Could be an infection, there are some antibotics which are okay.