Patient Education2 min read

Blood in the Stool (Rectal Bleeding)

Overview

Blood in the stool means bleeding somewhere in the digestive tract, from the stomach down to the anus. It may appear as bright red blood, dark maroon stool, or black tarry stool, and sometimes it is invisible to the naked eye. Because the cause can range from minor to serious, blood in the stool should always be evaluated rather than assumed to be hemorrhoids.

Symptoms

Bright red blood on toilet paper, in the toilet or on the stool

Dark red or maroon stool

Black, sticky, foul-smelling stool (possible bleeding higher in the digestive tract)

Abdominal pain or cramping

Change in bowel habits or a feeling of incomplete emptying

Dizziness, fatigue or pallor from blood loss (anemia)

Common Causes

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Hemorrhoids and anal fissures

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Diverticular disease

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Inflammatory bowel disease (ulcerative colitis, Crohn's disease)

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Colon polyps and colorectal cancer

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Peptic ulcers or gastritis (causing black stools)

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Infections of the intestine or reduced blood supply to the colon

Self-Care Tips

Do not assume the bleeding is from hemorrhoids, even if you have had them before

Book an evaluation promptly, and do not wait for the bleeding to stop on its own

Write down how often it happens, the color, and any pain or weight change

Tell your doctor about blood thinners, aspirin or anti-inflammatory medicines you take

Do not stop prescribed blood thinners on your own; ask your doctor first

Stay up to date with colorectal cancer screening as advised for your age and risk

When to See a Doctor

Any blood in the stool should be evaluated by a doctor. Go to the emergency department immediately if there is heavy bleeding, black tarry stools, vomiting blood, dizziness or fainting, a fast heartbeat, or severe abdominal pain. A colonoscopy is the key test if you are over 45, or at any age if you have red flags such as weight loss, anemia, a change in bowel habits, persistent bleeding, or a family history of colorectal cancer or polyps.

How doctors investigate it

Your doctor will ask about the color and amount of blood, your bowel habits, medications and family history, and will usually examine the anus and rectum. A blood count checks for anemia. Colonoscopy is the key test because it lets the doctor see the whole colon, take biopsies and remove polyps. If bleeding is thought to come from higher up, an upper endoscopy of the esophagus, stomach and duodenum may be needed.

Treatment options

Treatment depends on the cause found. Hemorrhoids and fissures are often managed with dietary fiber, fluids and topical or office-based treatments. Polyps are usually removed during colonoscopy. Inflammatory bowel disease and ulcers are treated with medicines suited to the condition, and significant bleeding may require urgent endoscopic treatment or a blood transfusion. If a tumor is found, your doctor will coordinate the next steps with the appropriate specialists.

Frequently Asked Questions

Is blood in the stool always caused by hemorrhoids?

No. Hemorrhoids are a common cause, but they cannot be confirmed without an examination, and other conditions such as polyps, inflammatory bowel disease or colorectal cancer can cause the same symptom. Having hemorrhoids does not rule out another source of bleeding, so it should always be checked.

What is the difference between red blood and black stool?

Bright red blood usually comes from the lower digestive tract, such as the rectum, anus or colon. Black, tarry stool usually suggests bleeding higher up, for example from the stomach or duodenum. Both need medical assessment, and black stool or heavy bleeding needs urgent care.

Can blood be in the stool without me seeing it?

Yes. Slow bleeding may not be visible and can lead to iron-deficiency anemia, with tiredness and pallor. A stool test for hidden blood or a blood count may detect it, and a colonoscopy can look for the cause.