I just got back from a few days away and I noticed that my 8-month old cat has diarrhea. She seems to be acting normal, very playful and active. Should I worry?

Was she left alone for those few days... If the answer is yes then I would take her to the vet? If no , and you are sure she just started the diarrhea, then I would give her 24 hours to see if maybe it was something she may have eaten. Make sure she is at least drinking water. If you don't see her drinking, take a clear bowl mark the outside of it with tape or a marker so you can determine how much she is drinking or if at all.

Was she left alone for those few days...If the answer is yes then I would take her to the vet? If no , and you are sure she just started the diarrhea, then I would give her 24 hours to see if maybe it was something she may have eaten. Make sure she is at least drinking water. If you don't see her drinking, take a clear bowl mark the outside of it with tape or a marker so you can determine how much she is drinking or if at all.

Update... she was left alone for two days (the first time I've ever left her alone). After, I posted the question I found an entire bag of cat treats that she had ripped into and eaten while I was gone. I'm thinking this may be the cause but I'm still keeping a close eye on her. Hopefully, she just had a little too much fun while I was gone...