What could be causing this?

Attitude had another episode of diarrhea, Paul cleaned her rear end this time. She seems to get diarrhea once a week. One episode every week and then she's fine. If it happens again she's going to find herself at the vet's office, unless ya'll think it's serious enough to take her in sometime around now(as in when the office opens.) This has been going on for 3 weeks so she's had 3 runny poops over a 3 week period. Like I said it is one episode once a week and then she's fine, she has normal looking firm poop. Anyone have any ideas on this. The other 2 times I thought it was because I added salmon oil to her food as a supplement(which I had been doing daily for over a month when this popped up. I stopped doing it and when I did it again the same result happened), but this time we have no clue what caused it.

I'm feeding her Natural Balance Ultra premium, I give her brewer's yeast once a day. As far as I know Nuts is fine and not having any issues. I'd think if it was food it would be a lot more often than one episode once a week.

She is eating and drinking normal, using her litter box and except for the one episode of runny poop(and she does go in the litter box) a week she pees and poops just fine. She is active and plays, and is acting totally normal for her.

Any clues and is this serious enough that I need to get her in or can I wait a week and see if it occurs again? If it was more than once one episode once a week I'd be more worried about this.

Thanks in advance.

Taryn

My first thought is whether she's eating any houseplants or flowers? Since it's occasional, I'd be thinking about other things she might be getting into, or licking, or nibbling, besides her actual food....

I hope you can solve it soon!