What To Know About Blood in Diarrhea

Bloody diarrhea, also known as bloody stool or rectal bleeding, can be bright or dark red or tar-like. It can be a symptom of anal fissures, hemorrhoids, infections, inflammatory conditions, and, rarely, colorectal cancer.

Diarrhea is common and generally resolves on its own, but it's important to see a healthcare provider if you notice blood. A healthcare provider can diagnose the underlying cause and prescribe treatments, which can range from dietary changes to medications and surgery in severe cases.

What Does Blood in Diarrhea Look Like?

Depending on what's causing bloody diarrhea, you might see blood:

• Covering your stool
• In the toilet
• Only on the toilet paper after you wipe

Blood in diarrhea might be bright red, dark red, or even a super dark, tar-like color. The longer the blood sits inside the digestive tract, the darker it will be, as it spends more time interacting with digestive chemicals.

Bright red blood usually starts low in the colon or rectum and may indicate a condition like hemorrhoids. Seeing dark red blood in your diarrhea possibly means bleeding higher up in the digestive tract, which can indicate a more severe condition.

What Causes Bloody Diarrhea?

Bloody diarrhea can be the result of various health conditions. It can be a symptom of a temporary condition like anal fissures or infections. Blood in diarrhea can also be a sign of a chronic (long-term) health problem.

Anal Fissures

Anal fissures are minor cuts that appear on the anus that likely bleed bright red. You might see blood on the tissue or in the toilet, depending on how big the tear is or where it is.

Pain is the main difference between having bleeding hemorrhoids—which happen in the rectum—and an anal fissure. You probably have an anal fissure if pooping is painful and you see blood.

Anal fissures can occur for several reasons. They're usually seen after chronic constipation or straining. You push so hard to get stool out that you end up tearing the skin at your anus. Anal fissures also happen with chronic diarrhea and after childbirth.

Hemorrhoids

Hemorrhoids are swollen blood vessels at the bottom of your rectum. They're among the most common reasons you may see blood in diarrhea. Many people with hemorrhoids notice a small amount of bright red blood on their stool, toilet, or toilet paper.

Like anal fissures, hemorrhoids may cause pain during bowel movements. It can be difficult to distinguish between the two conditions based on symptoms.

Infections

Infections that may cause bloody stool include:

• Diverticulitis: This occurs when diverticula, or bulges of tissue in the colon's wall, form and become inflamed. You may need surgery to keep it from happening again if you have significant bleeding from diverticulitis.
• Gastrointestinal (GI) infections: The most common GI infections that cause rectal bleeding include infectious colitis and food poisoning.
• Sexually transmitted infections (STIs): Gonorrhea, chlamydia, herpes, and syphilis are the most common STIs that cause rectal bleeding.
  

Some Inflammatory Conditions

Bloody diarrhea can be a sign of inflammatory bowel disease (IBD). IBD is an umbrella term for disorders that cause chronic inflammation in the digestive tract. Bleeding is more likely with ulcerative colitis (UC) than Crohn's disease, which are the two primary types of IBD.

Another type of inflammation that can cause rectal bleeding is proctitis, or rectal inflammation. Proctitis may be part of IBD and can be caused by certain infections, such as STIs or food poisoning. Radiation proctitis can occur after a person receives radiation therapy to treat cancer.

Ulcers

Peptic ulcers are sores that may occur on the lining of the stomach or small intestine. One complication of peptic ulcers is bleeding caused by the ulcers breaking blood vessels. These ulcers can result in black or tar-like stools.

Colorectal Cancer

Dark brown or black stool or bright red blood on toilet paper might be signs of colorectal cancer. Colorectal cancer can cause bloody diarrhea or stool when the tumors leak blood.

The whole purpose of tumors is to keep growing. They tap into the blood supply to suck up all the nutrition to do so. Tumors can leak blood, which you might see inside the toilet, when they're sitting inside the digestive tract. This blood might also make your stool look darker than usual.

Causes in Children

Constipation is the most common cause of bloody diarrhea in children. Children can develop anal fissures or hemorrhoids if they have constipation for long periods, causing rectal bleeding.

Many of the causes of bloody diarrhea in adults are the same for children, including:

• IBD
• Infections
• Meckel diverticulum, or a pouch in the small intestine that's congenital (present at birth)
• Ulcers

Diagnosis

A healthcare provider will ask about your health history and symptoms when diagnosing rectal bleeding. They may also complete a physical exam.

Other testing might be necessary for diagnosis, including:

• Anoscopy: Examines the anal canal and lower rectum using a rigid tube
• Colonoscopy: Inspects the colon as a whole
• Diarrhea stool specimen culture: Determines what germs are responsible for infections that cause bloody diarrhea
• Sigmoidoscopy: Looks at the rectum and the lower large intestine
  

Treatments for Bloody Diarrhea

One goal of treatment is to ensure that you don't become dehydrated if you have diarrhea. You may drink diluted juices or drinks with electrolytes and eat bland foods like bananas, oatmeal, and toast.

Oral or intravenous (IV) rehydration therapy, which replaces fluids, can be helpful in cases of diarrhea. IV rehydration therapy is designated for severe cases of diarrhea. Severe rectal bleeding can also require giving blood.

Treatment for bloody diarrhea also varies based on what's causing it. Options can include stool softeners, for example, if you have anal fissures or hemorrhoids. Chemotherapy, radiation therapy, or surgery is available for people diagnosed with colorectal cancer.

Prevention

You can prevent bloody diarrhea in some cases like anal fissures, hemorrhoids, and infections. You may try some of the following:

• Avoid straining during bowel movements or sitting on the toilet for a long time
• Drink plenty of fluids
• Increase fiber in your diet
• Practice good hygiene, including handwashing and using condoms during oral, anal, and vaginal sex
• Use laxatives for hard stools

The mechanisms by which conditions like diverticulitis and IBD occur remain elusive. You cannot prevent IBD, but there are some steps you can take to minimize flare-ups, such as:

• Avoid smoking
• Exercise regularly
• Drink plenty of water
• Get plenty of sleep
• Keep a food diary to detect any foods that may trigger symptoms
• See a healthcare provider for regular screenings
• Stay up-to-date with vaccines, including the flu shot
• Take medication as a healthcare provider prescribes
• Talk to a healthcare provider about the best treatments for you

Complications

The primary complications of diarrhea are dehydration and electrolyte loss. You can develop symptoms if you develop these complications, such as:

• Brain damage
• Death
• Seizures

A Quick Review

Bloody diarrhea can have several causes, including anal fissures, hemorrhoids, or infections. Inflammatory diseases, ulcers, and, rarely, colorectal cancer can also cause blood in diarrhea. A healthcare provider can perform a physical exam and administer diagnostic tests to figure out the cause.

Most cases of rectal bleeding resolve on their own, and the prognosis for diarrhea is generally good. Staying hydrated if you have diarrhea, with or without blood, is important and can aid in recovery.