Blood in stool? 7 main reasons you may be experiencing rectal bleeding

Discovering blood in the toilet bowl or on toilet paper can be alarming. Your mind might immediately jump to worst-case scenarios, and it's completely natural to feel concerned. While rectal bleeding should never be ignored, understanding what causes it and when to see a doctor can help you make informed decisions about your health.

The truth is that rectal bleeding is more common than you might think. Fortunately, most cases are caused by mild conditions that are easy to treat.

However, because rectal bleeding can occasionally signal something more serious, such as colorectal cancer, knowing the difference between common causes and red-flag symptoms is essential for protecting your digestive health.

What does rectal bleeding look like?

Rectal bleeding refers to any blood that passes through the anus. The appearance of this blood—its color, amount and how it presents—can offer important clues about where the bleeding originates in your digestive system.

• Rectal bleeding bright red typically indicates bleeding from the lower digestive tract, including the rectum, anus or lower colon. This blood hasn't traveled far through your intestinal system, so it maintains its fresh, red appearance.
• Rectal bleeding dark red or maroon-colored often suggests bleeding from higher up in the colon or small intestine. The blood has had more time to break down slightly before exiting your body.
• Rectal bleeding with black, tarry stools (called melena) usually indicates bleeding from the upper gastrointestinal tract, such as the stomach or upper small intestine. The blood has been digested, which changes its appearance.

While color can offer clues, it’s not definitive. Brisk bleeding from higher in the digestive tract can sometimes still appear bright red, so it is always important to speak to your doctor.

Rectal bleeding causes

Rectal bleeding ranges from minor to serious, but it always deserves attention. While hemorrhoids and anal fissures cause the vast majority of cases, there are a few other reasons you might be experiencing blood in your stool.

1. Hemorrhoids

Hemorrhoids are swollen blood vessels in the rectal area, and they're responsible for most rectal bleeding cases. Nearly half of all adults over 50 will experience hemorrhoids at some point.

Hemorrhoids can develop internally or externally, causing bright red bleeding that typically appears on toilet paper or coating the stool, and straining, pregnancy or prolonged sitting are often contributing factors.

While hemorrhoids can be uncomfortable and sometimes painful, they often improve with time or simple treatment.

2. Anal fissures

Anal fissures are small tears in the anal lining that often result from passing hard stools during constipation. Anal fissures produce sharp pain during bowel movements, along with bright red rectal bleeding.

Most fissures heal on their own with proper care, including increasing fiber intake and staying hydrated. However, some fissures can be early sign for Crohn’s or other diseases, Fissures that don’t heal may require prescription ointments or further evaluation.

3. Constipation and diarrhea

Both ends of the bowel movement spectrum can cause rectal bleeding. Chronic constipation leads to straining and hard stools that can tear delicate tissue.

Conversely, severe or prolonged diarrhea irritates and inflames the intestinal lining, potentially causing bleeding and discomfort.

4. Inflammatory bowel disease

Conditions like ulcerative colitis and Crohn's disease, which are both types of inflammatory bowel disease (IBD), involve chronic inflammation of the digestive tract.

These conditions affect millions of Americans and frequently cause rectal bleeding accompanied by other symptoms such as abdominal cramping, diarrhea, weight loss and fatigue. Unlike temporary rectal bleeding issues, IBD typically requires ongoing medical care.

5. Diverticular bleeding

Diverticulosis occurs when small pouches form in the colon wall. If these pouches become inflamed (diverticulitis), they can bleed. This condition becomes more common with age and is often managed through dietary changes and, when necessary, medication or surgery.

But it is important to know that diverticular bleeding is different from diverticulitis. One can happen without the other. Diverticula can sometimes bleed, even without infection or inflammation. Diverticular bleeding occurs when small blood vessels weaken or rupture, leading to bleeding, and at times a significant amount.

6. Polyps and colorectal cancer

Colon polyps are growths in the intestinal lining that can bleed. While most polyps aren't cancerous, some can develop into colorectal cancer over time.

This is precisely why regular colonoscopy screenings are so important—they allow your doctor to identify and remove polyps before they become problematic.

Colorectal cancer itself can cause rectal bleeding, making it crucial not to dismiss persistent bleeding as "just hemorrhoids" without proper evaluation.

7. Blood thinners

If you are taking blood thinners, you are at increased risk for rectal bleeding, as these medications reduce the blood's ability to clot, making any internal bleeding harder to stop. Any blood in stool, black or bright red, should be reported to a doctor, as it can signal a serious underlying issue, especially when on these medications.

When should you see a doctor for blood in stool or rectal bleeding?

While occasional, minor bleeding from known hemorrhoids might not require immediate attention, there are times when you should see a doctor right away.

Seek emergency care if you experience:

• Heavy, continuous rectal bleeding
• Dizziness, fainting or confusion
• Rapid heartbeat or difficulty breathing
• Severe abdominal pain or cramping
• Cold, clammy skin

Schedule an appointment with your doctor if you notice:

• Rectal bleeding that occurs more than once
• Blood mixed throughout your stool rather than just on the surface
• Changes in bowel habits lasting more than a few days
• Unexplained weight loss
• Persistent abdominal pain or discomfort
• A family history of colorectal cancer or inflammatory bowel disease
• You're over 45 (or earlier if you have risk factors) and haven't had a recent colonoscopy

Only about 40% of people who experience rectal bleeding actually seek medical attention. Don't become part of this statistic—your health is worth the visit.

What to expect at your appointment

Your doctor will start by asking detailed questions about your symptoms, including when the bleeding started, how much blood you've noticed and any accompanying symptoms. They'll likely perform a physical examination, which may include a digital rectal exam.

Depending on your age, symptoms and risk factors, your provider might recommend:

• Colonoscopy or sigmoidoscopy to visualize the colon
• Blood tests to check for anemia
• Stool tests to detect hidden bleeding
• Imaging studies, if needed

These diagnostic tools help identify the exact source of bleeding and guide appropriate treatment.

Rectal bleeding treatment options

The right treatment for rectal bleeding depends entirely on the underlying cause. For minor issues like hemorrhoids or anal fissures, conservative at-home remedies often provide relief—including warm sitz baths, over-the-counter or prescription topical treatments, increased fiber intake and adequate hydration.

More persistent hemorrhoids may require medical or surgical procedures. Inflammatory bowel disease typically requires ongoing medication management and regular monitoring by a gastroenterologist. If polyps are discovered during a colonoscopy, they can often be removed during the same procedure.

For more serious conditions like colorectal cancer, treatment may involve surgery, chemotherapy, radiation or a combination of therapies. Your doctor will work with you to develop a treatment plan tailored to your specific diagnosis, symptoms and overall health.

Can you prevent rectal bleeding?

Prevention is always preferable to treatment. You can reduce your risk of many causes of rectal bleeding by:

• Eating a fiber-rich diet with plenty of fruits, vegetables and whole grains
• Drinking adequate water throughout the day
• Exercising regularly to promote healthy digestion
• Avoiding prolonged sitting on the toilet
• Not straining during bowel movements
• Following recommended colorectal cancer screening guidelines

The key is knowing your body and trusting your instincts. If something feels wrong or bleeding persists, don't hesitate to speak to a gastroenterologist.