Gastrointestinal (GI) bleeding is any type of bleeding that originates in the gastrointestinal tract.

GI bleeding is a symptom of a disease or condition, rather than a disease or condition itself.

Each year, approximately 100,000 people in the United States are hospitalized for upper gastrointestinal bleeding. Approximately 20-33% of GI bleeding episodes in Western countries involve the lower GI tract. Men are twice as likely as women to have upper GI bleeding.

Where GI Bleeding Occurs

Bleeding is commonly categorized based on its location:

Upper GI Bleeding

The upper GI tract includes:

• Esophagus (tube from mouth to stomach)
• Stomach
• First portion of the small intestine (duodenum)

Upper GI bleeding may present with vomiting blood or black, tarry stools.

Lower GI Bleeding

The lower GI tract includes:

• • Small intestine
  • Large intestine (colon)
  • Rectum
  • Anus

Lower GI bleeding often presents as bright red or maroon-colored blood passed with bowel movements.

Understanding You Digestive System

Acute vs. Chronic GI Bleeding

• Acute GI bleeding occurs suddenly and can be severe or life-threatening.
• Chronic GI bleeding involves small amounts of blood loss over time and may wax and wane.

Chronic bleeding is often harder to detect but can still cause significant health problems.

Signs and Symptoms of GI Bleeding

The amount of GI bleeding may be so small that it can be detected only by a laboratory test, such as the fecal occult blood test. Other signs of GI bleeding include:

• Dark, tarry stools
• Larger amounts of blood passed from the rectum
• Small amounts of blood in the toilet bowl, on toilet paper, or in streaks on the stool (feces)
• Vomiting blood

Massive bleeding from the GI tract can be dangerous and requires immediate medical attention. However, even small amounts of bleeding over time can lead to anemia, fatigue, weakness, and other complications if left untreated.

Identifying the cause of bleeding early allows for appropriate treatment and reduces the risk of long-term complications.

When to Seek Care

You should seek urgent medical evaluation if you experience:

• Vomiting blood
• Black or tarry stools
• Heavy or persistent rectal bleeding
• Dizziness, weakness, or fainting

If bleeding is ongoing or unexplained, a gastroenterology evaluation is recommended.

Frequently Asked Questions 

Is GI bleeding always serious?
Not always. Some causes are mild (like hemorrhoids), but bleeding can also be a sign of an ulcer, inflammation, polyps, or other conditions. Because the cause isn’t always obvious, new or recurring bleeding should be evaluated.

What does black, tarry stool mean?
Black, tarry stools (often called melena) can be a sign of bleeding higher in the digestive tract (such as the stomach or small intestine). This should be assessed promptly, particularly if you also experience weakness, dizziness, or shortness of breath.

What does bright red blood in the stool mean?
Bright red blood is more commonly associated with bleeding closer to the rectum or lower colon, but it can have multiple causes. If it’s new, recurrent, or significant, it’s worth medical evaluation.

Can GI bleeding be “hidden”?
Yes. Some GI bleeding is too small to see and is only detected with lab testing, such as a fecal occult blood test, or by blood work showing anemia (low blood counts).

Can GI bleeding cause anemia?
Yes. Even small amounts of blood loss over time can lead to iron deficiency anemia, which may cause fatigue, weakness, shortness of breath, or lightheadedness.

When should I go to the emergency room for GI bleeding?
Seek emergency care right away if you have vomiting blood, heavy rectal bleeding, black/tarry stools with dizziness or fainting, severe weakness, chest pain, or trouble breathing.

What tests are used to find the source of GI bleeding?
Evaluation may include blood work, stool testing, and procedures such as upper endoscopy and/or colonoscopy. Your provider will recommend testing based on symptoms, medical history, and risk factors.

Can medications cause GI bleeding?
Some medications can increase bleeding risk or irritate the GI tract, including NSAIDs (like ibuprofen/naproxen) and blood thinners. Do not stop prescribed medications without medical guidance. Talk with your provider.

What should I bring to my appointment?
Bring a list of current medications (including over-the-counter pain relievers), any recent lab results, and notes about your symptoms (when it started, how often, stool color, and estimated amount). How should I prep for a procedure?

If my symptoms improve, do I still need to be evaluated?
Sometimes bleeding slows or stops temporarily, even when the underlying cause remains. If you’ve had new, unexplained, or recurring bleeding, especially with fatigue or anemia, follow-up evaluation is recommended.

Safety note: If you’re experiencing severe symptoms (heavy bleeding, fainting, vomiting blood), seek emergency care.

Learn More

For additional information about GI bleeding, visit the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). 

Information from the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), the Colon Cancer Alliance, and