Blood in Your Stool: What It Means and What to Do About It

Blood in the stool is an abnormal, potentially serious condition in which blood is mixed in with a bowel movement or feces. The blood can arise from anywhere along the digestive tract, from the mouth to the anus. Bloody stool is often a sign of gastrointestinal (GI) bleeding due to injury or disease. Bright red or maroon-colored blood that passes with stool may be referred to as “hematochezia,” while “melena” describes black, tarry, and smelly stools.

Read on to learn more about potential causes and treatments for blood in your stool.

Blood in the stool can indicate a relatively mild condition like hemorrhoids or constipation, or it can be due to a serious condition such as esophageal varices or colon cancer.

The upper GI tract includes the esophagus, stomach, and duodenum. The duodenum is the upper part of the small intestine.

Potential causes of bloody stool related to the upper GI tract include:

• blood vessel malformation
• esophageal trauma
• gastritis
• gastroenteritis
• stomach cancer
• stomach varices
• swallowed blood from a nosebleed

The lower GI tract runs from the lower part of the small intestine to the anus. Causes of bloody stool related to the lower GI tract may include:

• anal fissure
• anal sex
• blood vessel malformation
• bowel ischemia or bowel obstruction
• colon cancer
• constipation
• diverticulosis
• gastroenteritis
• hemorrhoids
• inflammatory bowel disease (IBD), which includes Crohn’s disease and ulcerative colitis
• intestinal infection
• intestinal polyps or intestinal tumor
• Meckel’s diverticulum, an abnormal pouch near the lower end of the small intestine
• rectal prolapse

Bloody stool can also be a side effect of radiation therapy or certain medications, like low dose aspirin taken long term.

In some cases, bleeding may accompany a serious or life threatening condition, including:

• bleeding peptic ulcer
• food poisoning
• ruptured esophageal varices
• severe abdominal trauma

Blood in the stool can appear in various forms. Small amounts of bright red blood may be mixed inside the stool or show up on toilet paper after wiping the anus.

Visible blood clots can also be present. Blood in the stool is sometimes accompanied by open bleeding from the rectum.

Black, tarry stools may indicate that the blood is coming from the upper GI tract. As blood travels through the GI tract, secretions convert hemoglobin into an acid called hematin, which darkens the color of the blood.

Red or maroon-colored stools often originate from bleeding in the lower GI tract.

Depending on the underlying condition, blood in your stool may occur with other symptoms such as:

• abdominal pain or cramping
• abdominal swelling or bloating
• body aches
• diarrhea
• fatigue
• fecal incontinence
• nausea
• poor appetite
• rectal bleeding
• rectal pain
• urgent need to pass stool
• vomiting
• weight loss

To diagnose the underlying cause of bloody stool, doctors may begin by performing a physical examination and taking a detailed medical history. Determining whether hematochezia or melena is occurring is important to narrow down the part of the GI tract that may be involved.

If doctors suspect bleeding in the upper GI tract, they may perform an endoscopy to determine the cause and potentially treat the condition at the same time.

For lighter-colored bloody stool, a digital rectal exam may help doctors determine whether there are masses or hemorrhoids. A colonoscopy can allow doctors to visually examine the colon and rectum and potentially treat any bleeding.

In some cases, a diagnosis of the cause of blood in the stool can be delayed or missed because tiny amounts of blood may not be noticeable for long periods. Blood in the stool that is not immediately visible due to the small quantity is called fecal occult blood.

If doctors suspect fecal occult bleeding based on other symptoms, they may order a fecal occult blood test. This test involves assessing 1–3 stool samples to check for blood.

In the short term, treatment for bloody stool may involve IV fluids or blood transfusions, depending on the severity of the bleeding.

Depending on the underlying cause, doctors may prescribe certain medications to promote healing in the GI tract. Proton pump inhibitors (PPIs) may encourage healing by reducing damage from stomach acid, and a drug called “octreotide” may benefit people experiencing bleeding from esophageal varices.

Doctors may be able to treat bleeding in the lower GI tract during a colonoscopy. In some cases where medications or other therapeutic methods are insufficient, surgery may be necessary.

Over time, blood in the stool can lead to serious complications, including:

• anemia
• severe blood loss
• shock

A healthcare professional should evaluate any blood in the stool.

In some cases, bloody stool may occur with other symptoms that might indicate a serious or life threatening condition. Seek immediate medical care if you’re experiencing any of these serious symptoms:

• change in the level of consciousness
• confusion and disorientation
• difficulty breathing
• dizziness
• fainting
• fever higher than 101°F
• rapid pulse
• rigid, board-like abdomen
• severe abdominal pain
• vomiting blood or black material resembling coffee grounds
• weakness

Here are a few other common questions about blood in your stool. Saurabh Sethi, M.D., M.P.H., has reviewed the answers.

Certain foods, like beets or foods that contain red food coloring, may cause your stool to appear bloody but will not make you bleed. Contact your doctor if you have blood in your stool and have not eaten any red foods.

You should contact your doctor if you notice any blood in your stool. While it may result from a temporary minor condition, like constipation, it may also indicate a more serious condition.

The length of time that hemorrhoids bleed can change from person to person. However, if your symptoms have not resolved after 1 week, contact your doctor.

Blood in your stool can result from various conditions. If you’re experiencing bloody stool, contact your doctor. They can help you identify the cause and decide on a treatment plan.