Better safe than sorry, IMO.

When Charlie would get stressed out he would get diarrhea and it would have blood in it because... not quite sure how to word this but... the diarrhea was "acidic" or "hot" I guess and it just irritated his anus and made it bleed... it was bright red and it was a lot, lol.

If you're unsure, you can always put it in a ziplock baggie and take it in to have it analyzed by the vet. In some places you don't even have to call ahead or time or have an appointment.