There are several different causes of blood in the stool. Most of the time, this should be evaluated by your doctor
and sometimes it can be a serious medical emergency.
If you are having copious bleeding with your bowel movements, severe abdominal pain, or if you feel lightheaded or dizzy, these could all be signs of significant intestinal bleeding. In which case, you should immediately call an ambulance or go to the emergency room for immediate evaluation.
On the other hand, if this was just a small amount of bright red blood and if you otherwise feel well, you can go to see your primary care doctor
at your earliest convenience. By far the most common cause of bleeding like this are hemorrhoids, but other forms of anal irritation, such as an anal fissure can also cause bleeding. In some cases, small amounts of bleeding may be a sign of a cancer in the colon. Your doctor will be able to examine for signs of hemorrhoids or other obvious problems. They can also help you decide if additional workup might be needed. This workup could include a referral to a gastroenterologist
or a colonoscopy.
Call your doctor as soon as you can!