Patient education: Bloody stools (The Basics)

What are bloody stools? — "Stools" is another word for "bowel movements." If you have bloody stools, you might see bright red blood:

●On the toilet paper after wiping

●In the toilet after you go to the bathroom

●On the surface of or mixed in with your bowel movements

In some cases, bloody stools look more like black tar. Stools that look like tar are usually caused by bleeding high up in the digestive system (figure 1).

What causes bloody stools? — The 2 most common causes are not usually serious:

●Hemorrhoids – These are swollen blood vessels in the anus. Hemorrhoids can itch or hurt.

●Anal fissures – These are tears in the skin on the anus.

Sometimes, bloody stools are serious. They can be a sign of polyps (small growths), cancer, or other problems in the digestive system.

What other symptoms should I watch for? — These symptoms can help your doctor figure out what is causing your problem and if it is serious:

●Itching or pain in the anus

●Feelings of ripping or burning during bowel movements

●Fever, weight loss, and heavy sweating at night

●Diarrhea

●Feeling like you need to have a bowel movement, but not being able to go

●Belly pain

●Bowel movements that look black or dark red

●Changes in how often or how hard or soft your bowel movements are

●Bleeding that goes on for a long time or that comes back again and again

Should I see a doctor or nurse? — Yes. See your doctor or nurse right away if you notice any blood with your bowel movements. Most cases are not serious. But anyone with bloody stools should be seen by a doctor or nurse.

Are there tests I should have? — Your doctor or nurse will decide which tests you should have based on your age, other symptoms, and individual situation.

Here are the most common tests doctors use to find the cause of bloody stools:

●Rectal exam – Your doctor will look at the outside of your anus. They will also use a finger to feel inside the opening.

●Anoscopy – In the office, your doctor will put a small tube into your anus. The tube goes a few inches into the rectum (the lower part of the large intestine). It has a light on it so the doctor can see inside.

●Sigmoidoscopy or colonoscopy – For these tests, the doctor puts a thin tube into your anus. Then, they gently push the tube into your large intestine. The large intestine is also called the colon. The tube has a camera attached to it, so the doctor can look inside your intestines. During these tests, the doctor can also take samples of tissue to look at under a microscope (figure 2).

How are bloody stools treated? — Treatment depends on what is causing your bloody stools. You might not need treatment. If you do, treatments might include:

●Fiber supplements and medicines to keep your bowel movements soft

●Sitting in warm water a few times a day for about 15 minutes

●Creams and medicines that go on or inside your anus. These help with pain, itching, and swelling.

●More serious medicines for diseases of the digestive system

Can bloody stools be prevented? — If you have hemorrhoids, you can reduce the chances of getting bloody stools again by drinking lots of water and eating lots of fiber. Fiber is common in fruits, vegetables, and breakfast cereal (table 1). You might also need medicines to prevent constipation (trouble having bowel movements).

What if my child gets bloody stools? — In children and babies, bloody stools can be a symptom of:

●Tears in the anus (anal fissures) from large or hard bowel movements

●A condition that makes it hard to digest milk or soy

●Infection by a virus or bacteria, or food poisoning

●Diseases that affect the digestive system

●Foods and medicines that look like blood but aren't (table 2)

If you notice blood in your child's diaper or bowel movements, take them to see the doctor or nurse.

More on this topic

Patient education: Hemorrhoids (The Basics)
Patient education: Anal fissure (The Basics)
Patient education: Constipation in adults (The Basics)
Patient education: Constipation in children (The Basics)
Patient education: GI bleed (The Basics)

Patient education: Blood in the stool (rectal bleeding) in adults (Beyond the Basics)
Patient education: Blood in bowel movements (rectal bleeding) in babies and children (Beyond the Basics)
Patient education: Anal fissure (Beyond the Basics)
Patient education: Hemorrhoids (Beyond the Basics)