I've had a few cats that have had traces of blood in their stool at various times (sometimes lasting for a wk or so). The vet didn't find anything & said it can sometimes be caused by stress or a few other factors that are hard to control. The vet also reiterated that it only takes 1-2 drops of blood to make a blood streak on the stool and that many people overestimate how much blood they're seeing.
I've had other times where I noticed blood and also found worms
which I then treated him for. However, I'm talking about when nothing else is found to be wrong.
I've had other times where I noticed blood and also found worms