Bright Red Blood in Stool: Should I Worry?

Bright red blood in your stool is a sign of bleeding in the lower digestive tract. The colon, rectum, and anus are lined with blood vessels. Any injury to this tissue can lead to bright red rectal bleeding.

While concerning, it is most likely caused by a benign condition, like hemorrhoids or diverticular disease. However, bloody stool is also a symptom of colon cancer, which needs to be ruled out.

Call your healthcare provider if you see blood in the stool, whether in the stool, toilet water, or on the paper when you wipe.

This article reviews common causes of blood in the stool. It explains how bloody stool is evaluated, other concerning symptoms, and treatment.

When to Call Your Healthcare Provider

Any blood in the stool requires a call to your healthcare provider. Additional symptoms that should be evaluated promptly include:

• The bleeding is severe and won't stop.
• Bleeding persists for more than a few days.
• You have foul-smelling stools with a coffee-grain appearance.

Seek emergency care if the bloody stool is accompanied by:

• Shallow or rapid breathing
• Lightheadedness
• Severe nausea
• Fainting or loss of consciousness
• Fever or drop in body temperature
• Clammy and cold skin
• Fatigue or tired feeling
• Confusion or disorientation

These issues could be linked to serious infection or severe blood loss.

What Does Blood in Stool Look Like?

The blood in your stool may be different colors depending upon where in your colon it is located. For example:

• Bright red blood in your stool may indicate bleeding in the lower part of the colon.
• Darker red blood in the stool usually means bleeding in the higher part of the colon.
• Extremely dark or tar-like stool often indicates bleeding in the stomach.

Your healthcare provider may want to run tests based on the color of your stool.

Minor Causes of Rectal Bleeding

Bright red blood on the toilet paper is likely due to mild rectal bleeding. These common conditions can often be treated with at-home remedies but should still be discussed with your healthcare provider.

Hemorrhoids

Hemorrhoids are swollen blood vessels that can be inside or outside of the anus. They are a common, mostly harmless problem.

However, they are fragile and can bleed. Hemorrhoids are the number one cause of bright red blood smears on toilet paper.

You may or may not feel any discomfort with a hemorrhoid. Pregnancy and straining during a bowel movement are two common causes of hemorrhoids. They are easily treatable and may even resolve on their own.

Anal Fissure

An anal fissure is a small split or tear in the lining of the anus that can cause bright red blood in the stool.

This thin moist tissue (mucosa) can tear when you pass large, hard stools, have prolonged diarrhea, or if your anal sphincter is too tense. Anal sex can also cause tearing. Once this tissue tears, it is often difficult to heal. It may bleed repeatedly and can be extremely painful.

Treatment for anal fissures starts by working to prevent constipation and hard stool. Numbing cream, Preparation H, and sitz baths can help to ease the pain. In more troublesome cases, Botox injections or surgery is needed.

Constipation

Constipation and straining to pass a large bowel movement can lead to smears of bright red blood on the toilet paper. Causes of constipation include:

• Not drinking enough water
• Low-fiber diets
• Lack of exercise
• Changes in routine
• Eating too much dairy
• Stress
• Holding your bowel movements
• Certain medications
• Certain health conditions
• Pregnancy

Let your healthcare provider know if you are straining to pass bowel movements.

Blood in the Stool Not Due to Cancer

Bright red blood in the stool can be a sign of multiple noncancerous conditions. Your healthcare provider can help you determine whether your bleeding is a result of one of these conditions.

Inflammatory Conditions

Certain inflammatory diseases in the colon can cause bright red or dark red blood in the stools. These include:

• Inflammatory bowel disease (IBD)
• Crohn’s disease
• Ulcerative colitis
• Diverticular disease

Colon Polyps

Colon polyps are growths on the inside wall of the colon. Most polyps are benign (noncancerous) and do not cause any symptoms.

Polyps can and do bleed, though, particularly larger ones. If your healthcare provider suspects a polyp, they will want to order a colonoscopy to investigate and remove the polyp. Polyps that aren't removed can lead to colon cancer.

Bowel Infections

Untreated bowel infections, such as an Escherichia coli (E. coli) infection, can cause bloody diarrhea and abdominal pain. E. coli can stem from consuming undercooked meats or unpasteurized juice and dairy products. The infection requires antibiotic therapy.

Blood in the Stool Due to Cancer

Colon cancer can cause blood in the stool. However, in the early stages, most colon cancers do not generate any symptoms.

If the visible blood in your stool is from colon cancer, it is most often from the left side of the colon (including the descending colon, sigmoid colon, or rectum). Tumors in the right side of the colon (in the ascending colon) are less common, and being flatter, they usually do not present with noticeable bleeding until the cancer is more advanced.

Cancer-related bleeding may vary in color, depending on the location of the cancer. Bleeding from cancer that is lower in the bowel or is in the rectum may be bright red. Blood that comes from higher up in the bowel may be dark red or black. 

Blood that is related to cancer is more consistent than blood that comes from hemorrhoids. It usually occurs regularly and gets worse over time. 

How Is Rectal Bleeding Diagnosed?

Your healthcare provider will complete a physical exam to look for any visible causes of rectal bleeding, like hemorrhoids or anal abrasion. They will also take your medical history. Then, they may order tests to investigate the cause further, even if it is obvious.

Your healthcare provider might order the following tests:

• Complete blood count (CBC): This blood test can show how much blood you may have lost.
• Fecal occult blood test (FOBT) or fecal immunochemical test (FIT): These stool tests check for the presence of blood.
• Colonoscopy: In this procedure, a healthcare provider uses a scope to look inside the entire colon. This test allows the healthcare provider to see and remove any polyps in the colon lining.
• Sigmoidoscopy: This test is similar to a colonoscopy, but looks only at the lower part of the colon, including the sigmoid colon and the rectum.
• Imaging Studies: Images from X-rays, Ultrasounds, MRIs, and CT scans of the lower intestinal tract may show any abnormalities in the colon.

Following the test(s), your healthcare provider will discuss the findings with you. They may potentially order further testing if imaging found abnormalities. Based on the results, they can develop a treatment plan, as needed.

Questions Your Doctor May Ask

The best action you can take now is to make an appointment with your healthcare provider. Prepare for your visit with answers to these questions:

• Was the blood in the stool, toilet bowl, or on the toilet paper?
• Was the blood bright red or dark red?
• Approximately how much blood did you see? (Keep in mind, a drop of blood in a toilet bowl will turn all of the water red.)
• Did you have to strain to pass the bowel movement?
• How frequently do you have bowel movements?
• Do you have other symptoms?
• When was your last colon cancer screening or colonoscopy?
• Do you have a history of polyps or a family history of polyps?

How Is Rectal Bleeding Treated?

The treatment for bright red blood in stool focuses on the underlying cause. Minor bleeding from hemorrhoids or a fissure often goes away on their own or with at-home care. More serious causes will require medical treatment.

For bleeding due to hard stools and tears, treating constipation is the first step. Over-the-counter stool softeners, like Colace (docusate), can help in the short term. Dietary changes, gradually increasing your fiber intake, drinking more water, and getting regular exercise can help long term.

Some causes, like polyps, can be treated during a colonoscopy. Inflammatory conditions may require prescription medications to relieve the underlying cause of rectal bleeding.

Colorectal cancer typically requires surgery, followed by targeted therapies, including chemotherapy and immunotherapy.

Summary

Bright red blood in your stool can be caused by a wide range of conditions. Often, bleeding during a bowel movement is a clue to benign conditions like hemorrhoids, constipation, or polyps.

However, bright red blood in your stool can also be caused by infections, intestinal diseases, and colorectal cancer. Blood in the stool should always be evaluated by a healthcare provider.

To find the underlying cause, your healthcare provider may order blood work and a colonoscopy. Treatment will depend on the cause, and minor rectal bleeding may clear up on its own.