siezures 2nd part

I went to the vet yesterday about what I thought may have been seizures in the night because Trapper had brought up alot of bile. The vet changed her food and says it was probably something she found in the yard and ate and not necessarily seizures but to watch her close and bring her in if it happens again. He says they should't bring up bile after a seizure but I know she did last time. My family is going skiing next week and my neighbor was going to let her in and out and she would be alone at night but now I am afraid to do that even though the other dogs will be here for company I am afraid she will stress when we dont come home at night. Does anyone think stress can bring on seizures? The two times she had them we were late getting home and she had been alone longer than usual which made me think she may have gotten upset.