Bloody Diarrhea: Causes and Treatment

Medically Reviewed By Cynthia Taylor Chavoustie, MPAS, PA-C
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Bloody diarrhea is blood mixed in with loose, watery stools. The blood can come from anywhere along your digestive tract, from the mouth to the anus. Bloody diarrhea is often a symptom of gastrointestinal bleeding due to injury or disease. Bloody diarrhea can occur in all age groups and populations. If you have bloody diarrhea, you should speak with your doctor right away.

Read on to learn more about the causes, accompanying symptoms, and treatment options related to bloody diarrhea.

What are the causes of bloody diarrhea?

A woman holds her stomach and gut
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Mild underlying conditions, such as hemorrhoids or anal fissures, can cause bloody diarrhea. However, bloody diarrhea can also result from a life threatening condition, such as a serious intestinal infection or colon cancer.

Gastrointestinal tract causes

Some causes of bloody diarrhea related to the gastrointestinal tract include:

Other causes

Side effects from certain medications and radiation therapy can also cause bloody diarrhea.

Potentially serious or life threatening causes

A healthcare professional should evaluate any type of bloody stool. Certain serious conditions will require immediate treatment, including:

  • severe intestinal infections
  • severe abdominal trauma
  • colon cancer

What can bloody diarrhea look like?

The term “bloody diarrhea” most often describes very loose, watery stool mixed with bright red or maroon blood.

Diarrhea that contains bright red or maroon blood is called “hematochezia.” It often originates from bleeding in the lower gastrointestinal tract, which covers the large intestine down through the rectum and anus.

The term “melena” describes black, tarry diarrhea. Although melena is technically blood with stool, medical professionals do not typically consider it bloody diarrhea. Melena usually indicates that the blood is coming from the upper gastrointestinal tract. Blood that travels a long way through the body is broken down by bacteria, causing the blackish coloring.

What other symptoms might occur with bloody diarrhea?

Depending on the underlying condition, bloody diarrhea may occur with certain other symptoms, including:

Serious symptoms that might indicate a life threatening condition

In some cases, bloody diarrhea may occur with other symptoms that indicate a serious or life threatening condition that requires immediate evaluation in an emergency setting.

Seek immediate medical care or call 911 if you have bloody diarrhea and any of these symptoms:

How do doctors diagnose bloody diarrhea?

There are several tests that doctors can use to diagnose the cause of bloody diarrhea.

They may first perform a fecal occult blood test (FOBT) if you have concerning symptoms but the amount of blood in your stool is too small to be seen with the naked eye. If the FOBT is positive, they will typically order blood tests to make sure that you have not lost an excessive amount of blood.

Doctors may also need a stool sample to check for bacteria or parasites that could indicate an infection.

If bloody diarrhea occurs with abdominal pain, the following imaging tests can also help confirm a diagnosis.

  • Abdominal CT scan: This scan can create detailed images of your gastrointestinal tract for doctors to evaluate.
  • Upper or lower gastrointestinal series: For these tests, you will swallow a liquid called barium, which will make your gastrointestinal tract show up more clearly in images.
  • Angiogram: This is a type of X-ray that allows doctors to assess your blood flow.
  • Radionuclide scan: For this scan, a doctor will inject a radioactive material into your body to help them locate the bleeding.

If unusual findings on the CT scan warrant further evaluation, or if the doctor is still unable to confirm a diagnosis, endoscopy may be necessary. Endoscopy is a common diagnostic test for chronic bloody diarrhea. It involves inserting a flexible tube with a camera into your mouth or anus to evaluate your gastrointestinal tract.

What are the treatments for bloody diarrhea?

Treatment for bloody diarrhea will depend on the underlying cause. For some causes, such as hemorrhoids or anal fissures, doctors may recommend a topical cream or ointment. Bacterial infections may require antibiotics, while more serious conditions — such as blockages or colon cancer — may require surgery.

If bloody diarrhea is a side effect of a medication you are taking, your doctor may recommend that you stop taking it or try a different medication.

People can easily become dehydrated when they have diarrhea, so it is important to drink plenty of fluids. In severe cases, some people may need to receive IV fluids in the hospital.

What are some potential complications of bloody diarrhea?

Without treatment, bloody diarrhea can lead to serious complications, including:

FAQ

These are a few other commonly asked questions about bloody diarrhea. Cynthia Taylor Chavoustie, MPAS, PA-C, has medically reviewed these answers.

Is bloody diarrhea an emergency?

Bloody diarrhea can be an emergency if it results from a serious condition, such as a serious intestinal infection or colon cancer.

Although not all causes are serious, you should still contact a doctor for an evaluation if you have bloody diarrhea.

What should I eat if I have bloody diarrhea?

If you have bloody diarrhea and are unable to get immediate medical attention, eating soft, bland foods can help relieve your symptoms.

Can stress and anxiety cause bloody diarrhea? 

Although stress and anxiety can cause diarrhea, blood in your diarrhea typically does not result from stress. The blood usually comes from an injury, disease, or infection somewhere in your digestive tract.

Summary

Bloody diarrhea is loose, watery stool with blood mixed in. The blood may be bright red, dark red, or black, depending on where the bleeding occurs in your digestive tract. Some causes of bloody diarrhea include inflammatory bowel disease, gastroenteritis, diverticulitis, and colon cancer.

Doctors typically diagnose bloody diarrhea by taking a stool sample for analysis. They may also need to use imaging scans to locate the bleeding or look inside your gastrointestinal tract using endoscopy. Treatment for bloody diarrhea will depend on the cause but may include topical creams, antibiotics, or surgery.

Talk with your doctor if you have bloody diarrhea.

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Medical Reviewer: Cynthia Taylor Chavoustie, MPAS, PA-C
Last Review Date: 2022 May 27
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