Lizz, anytime blood is found in the fecal material the issue should be checked out with a doctor. Call and make an appointment.
It could be something as simple as internal hemorrhoids or as serious as cancer. Never mess around with this type of a symptom. See your doctor to rule out anything of a serious nature and always remember that if it is something serious it is almost 100% curable if caught early ,so the key is to be checked by your doctor and do not self diagnose anytime blood is involved. That could be precious time wasted.