Dog has diarrhoea and just started vomiting

My dog (approximately 5 year old german shepherd husky mix, spayed) has been having watery diarrhoea since Wednesday and we've been trying a bland diet since Thursday to try and help (we took her to a vet Thursday and they suggested the bland diet and said to come back if things aren't better by tomorrow). We've been feeding boiled chicken and rice and that's not changed the diarrhoea situation, and this morning she vomited. Having looked at everything, it seems like her stomach isn't processing the rice, as it's just sorta been there in both the poop and in this morning's vomit completely undigested. Her dinner last night was half a can of Blue Buffalo chicken wet food with enough warm water to make a decent soup of it (this is usually what we give her of an evening, just rotating flavours). We gave her her usual worming tablet (simparica trio) this morning despite being about a week early because my husband believes the symptoms line up, though I'm not sure. She seems fine in herself, she's still happy and playful and loving her outside time in the yard, and she doesn't seem to be in any pain, it's just overall unpleasant for everyone involved. We don't think she's eaten anything she shouldn't have recently, but I'll admit she don't always fully supervise her when she's in the backyard, though it's not exactly a huge area and I don't think there's anything back there that'd do her any sort of damage, we did check it out to make sure when we moved in a couple months ago. We will likely take her to the vet again tomorrow but we would like to know if there are any suggestions of what it could be in the meantime.