What is bloody stool?

Blood in the stool is an abnormal, potentially critical condition in which there is blood 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 bleeding due to injury or disease. Stools that contain bright red or maroon-colored blood may be referred to as hematochezia, while melena is used to describe black, tarry, and smelly stools. Bloody stool can occur in all age groups and populations.

Blood in the stool can appear in a variety of forms. There may be small amounts of bright red blood that is mixed inside the stool or that shows 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 (rectal bleeding). Blood in the stool can be in such small quantities that it cannot be seen by the naked eye but can be detected by stool tests. This is called fecal occult blood, which may indicate a serious condition.

Many other symptoms can occur with blood in the stool depending on the cause of the bleeding. Symptoms often involve the gastrointestinal system but can involve other body systems as well. It is important to talk with your health care professional about any other symptoms you are experiencing.

What other symptoms might occur with bloody stool?

Depending on the underlying disease, disorder or condition, bloody stool may occur with other symptoms including:

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

Serious symptoms that might indicate a life-threatening condition

In some cases, bloody stool may occur with other symptoms that might indicate a serious or life-threatening condition that should be immediately evaluated in an emergency setting. Seek immediate medical care (call 911) if you, or someone you are with, are exhibiting any of these life-threatening symptoms:

Change in level of consciousness
Confusion and disorientation
Difficulty breathing
Dizziness
Fainting
High fever (higher than 101 degrees Fahrenheit)
Rapid pulse
Rigid, board-like abdomen
Severe abdominal pain
Vomiting blood or black material (resembling coffee grounds)
Weakness (loss of strength)

What causes bloody stool?

Blood in the stool can indicate a relatively mild condition, such as hemorrhoids or constipation, or it can be due to a serious, even life-threatening condition, such as esophageal varices or colon cancer. Certain medications, such as aspirin, can also cause bloody stool.

Black, tarry stools usually indicate that the blood is coming from the upper gastrointestinal tract (esophagus, stomach and duodenum), while red or maroon-colored stools often originate from bleeding in the lower gastrointestinal tract (colon, rectum and anus). Bloody stool that is associated with dizziness, diarrhea, or vomiting blood should be immediately evaluated in an emergency setting. However, 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 of time.

Upper gastrointestinal tract causes of bloody stool

Causes of bloody stool related to the upper gastrointestinal tract include:

Bleeding peptic ulcer
Blood vessel malformation
Esophageal trauma
Esophageal varices
Gastritis
Gastroenteritis
Stomach cancer
Stomach varices
Swallowed blood from nosebleed

Lower gastrointestinal tract causes of bloody stool

Causes of bloody stool related to the lower gastrointestinal tract include:

Anal fissure
Anal sex
Blood vessel malformation
Bowel ischemia or bowel obstruction
Colon cancer
Constipation
Diverticulosis
Gastroenteritis
Hemorrhoid
Inflammatory bowel disease (Crohn’s disease or ulcerative colitis)
Intestinal infection (food poisoning)
Intestinal polyps or intestinal tumor
Meckel’s diverticulum (an abnormal pouch near the lower end of the small intestine)
Rectal prolapse

Other causes of bloody stool

Bloody stool can be caused by:

Medication side effects
Radiation therapy

Serious or life-threatening causes of bloody stool

Any type of blood in the stool should be evaluated by a health care professional. In some cases, bleeding may accompany a serious or life-threatening condition including: