What Causes Rectal Bleeding?

Rectal bleeding occurs when blood passes from the anus or rectum during or after a bowel movement. It may appear as bright red blood on toilet paper, blood coating the stool, or blood dripping into the toilet bowl.

Rectal bleeding is a symptom rather than a disease. It can result from several conditions affecting the anus, rectum, or colon.

Hemorrhoids

Hemorrhoids are the most common cause of rectal bleeding.

They occur when veins in the rectum or anus become swollen and enlarged due to increased pressure.

Signs of Hemorrhoid Bleeding

• Bright red blood during bowel movements
• Blood on toilet paper
• Blood dripping into the toilet bowl
• Itching or swelling around the anus

Learn more:
👉 Hemorrhoids

Anal Fissures

An anal fissure is a small tear in the lining of the anus.
It often occurs after passing hard stools or during episodes of constipation.

Symptoms of Anal Fissures

• Sharp pain during bowel movements
• Bright red bleeding
• Burning sensation after passing stool

Fissures are common and usually heal with medical treatment and dietary changes.

Colon Polyps

Colon polyps are abnormal growths in the lining of the colon.
Many polyps cause no symptoms, but some may lead to bleeding.

Polyps are important because certain types may develop into colorectal cancer over time.

Doctors often detect and remove polyps during colonoscopy.

Diverticular Disease

Diverticula are small pouches that develop in the colon wall.
When one of these pouches bleeds, patients may experience sudden painless rectal bleeding.

Diverticular bleeding can sometimes produce a large amount of blood and may require medical evaluation.

Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) includes conditions such as:

• Ulcerative colitis
• Crohn’s disease

These conditions cause chronic inflammation of the colon and rectum.

Symptoms of IBD

• Rectal bleeding
• Diarrhea
• Abdominal pain
• Urgency to pass stool

Treatment focuses on controlling inflammation and preventing flare-ups.

Colorectal Cancer

Although less common, rectal bleeding may be an early symptom of colorectal cancer.

Other warning signs may include:

• Change in bowel habits
• Unexplained weight loss
• Persistent abdominal discomfort
• Fatigue from anemia

For this reason, persistent rectal bleeding should always be evaluated by a physician.

Other Possible Causes

Several additional conditions may also cause rectal bleeding:

• Proctitis (inflammation of the rectum)
• Angiodysplasia (abnormal blood vessels in the colon)
• Gastrointestinal infections
• Radiation injury to the rectum

A medical evaluation is often necessary to determine the exact cause.

When to See a Doctor

Rectal bleeding should be evaluated if it:

• Occurs repeatedly
• Is associated with abdominal pain
• Appears mixed within stool
• Causes dizziness or weakness
• Occurs in individuals over age 45

Even small amounts of bleeding should not be ignored.

Learn more about symptoms:
👉 Rectal Bleeding Symptoms

How Doctors Diagnose the Cause

Doctors may use several tests to determine the source of rectal bleeding.

Common diagnostic procedures include:

• Anoscopy
• Flexible sigmoidoscopy
• Colonoscopy

These procedures allow physicians to directly examine the rectum and colon.

Learn more:
👉 Rectal Bleeding Procedures

Learn More About Rectal bleeding

You may also explore these guides:

• Rectal bleeding Overview
• Rectal bleeding Symptoms
• Rectal bleeding Procedures
• Rectal bleeding FAQ
• Rectal bleeding Images & Diagrams