Lulu has the runs after vaccinations

Last Friday afternoon I took my little Lulu in for her 4-month FVRCP booster shot. Oh and the vet also gave her the rabies vaccination without asking me, he just casually mentioned it after the fact. I told him I was going to go back to the shelter for the free shot there, so at least he waived the charge.

Back to my question. Is it normal for kittens to develop diarrhea after either of these vaccines? Lulu uses the litter but often comes out needing a bath.

At the same time I should add that I have been gradually switching her kibble from Hill's Science Diet (from the shelter) to Wellness kitten. The transition was completed yesterday, but her diarrhea started Saturday.

It seems like there's too much going on for her little tummy to handle. What can I do? I will call the vet later when he opens, but in the meantime i was hoping for some advice from you cat lovers here.

Another thing to think of she may have picked up a bug at vets. I haven't had any shots done in a few years now, but do remember some of them being tired for a day.

Wouldn't that be something?!? I thought about that too, but is that even possible?

I called the vet and he said it could be one or the other or a combination of both

I got a pack of Bene-bac powder and mixed into her lunch. Lulu ate it al up, now it's wait and see.

Update: Lulu still has diarrhea. She's still under 5 pounds, so I gave her a teaspoon full of Bene-bac powder mixed into her food on Wednesday and Thursday. The package says so give it every other day, but I read posts where Carolina suggests giving it every day. So I tried a combination, giving it for 2 consecutive days and then taking a day off yesterday. I suppose that day off was a bad idea since Lulu pooped all over her legs last night While her poops were squishy on the other days, at least she didn't soil herself.

Also, I'm thinking it has to be the food, maybe I made the switch too fast. It took about 5-6 days. Should I stick with it or switch back?