Gastrointestinal (GI) Bleed: Causes and Treatments

Gastrointestinal (GI) bleeding is a symptom of a disease, condition, or injury affecting any part of the gastrointestinal tract. The GI tract includes the esophagus, stomach, small intestine, colon (large intestine), rectum, and anus. 

GI bleeds have many possible causes, ranging from minor acute (temporary) problems to more serious or chronic conditions.

GI bleeds are common, accounting for over 300,000 hospital admissions annually in the United States. Understanding the common signs and symptoms of GI bleeding can help you recognize when to seek medical care. 

Healthcare providers categorize GI bleeds into two types: upper GI bleed and lower GI bleed, depending on where they occur in the digestive tract.

About 70% of all GI bleeds occur in the upper GI tract—the esophagus (the tube that connects your mouth to your stomach), stomach, or duodenum (the first part of the small intestine). A lower GI bleed occurs in the lower GI tract—the bottom portion of the small intestine, colon (large intestine), rectum, or anus. 

The signs and symptoms of a GI bleed depend on its severity and location and may include:

• Abdominal pain or cramping
• Vomit with bright red blood
• Vomit that looks like coffee grounds
• Black, tarry stool
• Bright red or dark blood or blood clots mixed with stool 
• Small amounts of blood on toilet paper after wiping or in the toilet bowel after a bowel movement
• Dizziness or lightheadedness 
• Shortness of breath 
• Weakness 
• Fatigue

Acute vs. Chronic GI Bleed Symptoms 

An acute GI bleed develops suddenly and often involves heavy bleeding. Significant blood loss can lead to shock, causing symptoms such as: 

• Difficulty breathing 
• Chest pain
• Little to no urination
• Rapid heart rate 
• Drop in blood pressure
• Fainting or loss of consciousness 

A chronic GI bleed typically involves minor but persistent bleeding that can cause anemia (a lack of healthy red blood cells). This can lead to symptoms such as:

• Fatigue
• Shortness of breath, especially during physical activity 
• Lightheadedness 
• Pale skin
• Cold hands and feet

Many acute and chronic conditions cause gastrointestinal bleeding. The most common causes include: 

Peptic Ulcers

Peptic ulcers are open sores that develop on the lining of the stomach or duodenum (upper small intestine) and are the leading cause of upper GI bleeding.

They develop due to an infection with Helicobacter pylori (H. pylori) bacteria or after prolonged use or high doses of nonsteroidal anti-inflammatory drugs (NSAIDs). Inflammation from infection or NSAID use erodes the protective mucosal lining of the stomach and duodenum, leading to ulcers that can bleed.

Peptic ulcer symptoms can include: 

• Pain or discomfort in the upper abdomen, between the belly button and breastbone 
• Feeling full quickly or uncomfortably full after eating a meal 
• Nausea and vomiting
• Bloating 
• Belching 

Esophageal Varices 

Esophageal varices are enlarged veins in the esophagus (food pipe) that develop when blood flow through the liver is restricted in people with liver disease, such as cirrhosis. This blockage causes portal hypertension (high blood pressure in the blood vessels around the liver), forcing blood to find new pathways through smaller veins, which can enlarge and weaken over time.

If the veins rupture, they can cause severe and life-threatening bleeding. Variceal bleeding accounts for 10-30% of all upper GI bleeds. 

Esophageal varices do not usually cause symptoms until a GI bleed develops. Most people with esophageal varices have chronic liver disease, which may cause symptoms such as: 

• Swelling in the legs and abdomen 
• Itchy skin 
• Jaundice (yellowing of the skin and eyes) 
• Bruising easily 
• Dark-colored urine

Diverticular Disease 

Diverticular disease is the most common cause of lower GI bleeding. Diverticulosis occurs when diverticula (small pouches) form on the colon’s lining and bulge outward through weak spots. It is common, especially in older age, affecting more than one-third of people ages 50-59 and more than two-thirds of people over age 80. 

Most people with diverticulosis have no symptoms. Diverticular bleeding occurs when a small blood vessel within the wall of one or more of these pouches bursts, causing severe, sometimes life-threatening GI bleeding. 

The small pouches of diverticulosis sometimes become inflamed, causing a separate condition called diverticulitis to develop. This can result in symptoms such as bloating, constipation or diarrhea, lower abdominal pain and cramping (typically on the left side), fever, chills, nausea, and vomiting.

Gastrointestinal Cancers

Cancer that develops in certain parts of the gastrointestinal tract, including colorectal, gastric, and esophageal cancer, can cause GI bleeding. Bleeding can occur when blood vessels within the tumor bleed or when the tumor grows and damages the affected organ’s tissues or blood vessels. 

Tumors in the GI tract often cause occult (hidden) bleeding, but they can also cause more visible bleeding. Visible bleeding can include bloody stools or stools mixed with blood that appears bright red, maroon, dark brown, or black, depending on where the bleeding occurs in the GI tract.

Symptoms of GI cancers vary depending on the type of cancer, tumor size, and location. Common symptoms can include:

• Unintended weight loss
• Weakness
• Fatigue 
• Change in bowel habits 
• Loss of appetite 
• Bloody stool 
• Nausea and vomiting 

Inflammatory Bowel Disease (IBD) 

Inflammatory bowel disease (IBD), including Crohn’s disease and ulcerative colitis, causes chronic inflammation in the digestive tract. This can damage intestinal tissues and cause ulcers to form on the intestinal lining.

Along with bloody stools and rectal bleeding, IBD can also cause symptoms such as:

• Abdominal pain and cramping
• Frequent bowel movements
• Chronic diarrhea, constipation, or a combination of both 
• Bowel movement urgency 
• Tenesmus (feeling of incomplete bowel movements) 
• Nausea or vomiting

Hemorrhoids and Anal Fissures

Hemorrhoids and anal fissures are common causes of minor lower GI bleeding. Hemorrhoids are swollen veins in the lower rectum and anus that can develop when there is too much pressure on the veins around the anus, causing them to swell. This pressure typically occurs from straining during bowel movements or chronic constipation. Common hemorrhoid symptoms include: 

• Bright red blood in stool, the toilet bowel, or on toilet paper after bowel movements (usually painless)
• Itching or burning around the anus
• Discomfort when sitting 
• Protrusion of tissue outside the anus (such as a skin tag)

Anal fissures are small tears in the lining of the anus that often develop due to chronic diarrhea or from passing large, hard stools. Anal fissures can cause symptoms such as: 

• Sharp pain during and after bowel movements
• Bright red blood on toilet paper or in stool
• Skin tag near the anus (may develop in chronic cases)

Less Common Causes

Other possible causes of GI bleeding include: 

• Angiodysplasia: This condition occurs when abnormal blood vessels develop within the lining of the GI tract. These blood vessels can cause a slow GI bleed that starts and stops intermittently. 
• Mallory-Weiss syndrome: This is a tear in the mucosal lining of the GI tract, usually where the esophagus meets the stomach. It causes severe upper GI bleeding and symptoms like vomiting blood or vomit that looks like coffee grounds and dark, tarry stools. 
• Dieulafoy’s lesion: This rare cause of upper GI bleeding occurs when an abnormally large blood vessel within the GI tract lining (usually the stomach) erodes and bleeds without other abnormalities or diagnoses, such as peptic ulcers.

See a healthcare provider if you have any signs of a GI bleed, including:

• Bloody stool or blood on toilet paper or in the toilet bowl after a bowel movement 
• Black, tarry stool (a sign of old blood/bleeding in the upper GI tract) 
• Vomiting blood or vomit that looks like coffee grounds 

Seek immediate medical attention or call 911 if you have excessive bleeding or if the bleeding increases in frequency. Symptoms of significant blood loss and signs of shock may include: 

• Rapid heart rate 
• Shortness of breath or difficulty breathing 
• Chest pain
• Little to no urination
• Drop in blood pressure
• Fainting or loss of consciousness 

Gastroenterologists, medical doctors specializing in GI tract conditions, can diagnose and manage GI bleeding. They may perform diagnostic tests to determine the cause and location of the bleed, such as:

• Blood tests: Measure your blood cell count and iron levels 
• Stool tests: Identify occult (hidden) blood in the stool 
• Endoscopy: Examine the upper GI tract, including the esophagus, stomach, and duodenum 
• Colonoscopy: Examine the lower GI tract, including the colon and rectum
• Capsule endoscopy: Involves swallowing a small capsule with a camera to help visualize the small intestine
• Imaging scans: Includes abdominal X-ray, computed tomography (CT), and magnetic resonance imaging (MRI) scans to visualize the GI tract and surrounding structures 

Treatment for a GI bleed focuses on stopping the bleeding and addressing the underlying cause to prevent further blood loss. The specific treatment approach depends on the severity of the bleeding and the cause. 

A sudden, acute GI bleed causing significant blood loss requires immediate medical attention and treatment to stop the bleeding and prevent complications. When this happens, treatments may include:

• Supplemental oxygen through a mask on your nose
• Blood transfusions to replenish the body’s blood supply 
• Intravenous (IV) fluids to prevent dehydration and sudden blood pressure drops 
• Angiogram (an imaging test to see blood flow through the veins and arteries) to find the source of the GI bleed and inject medications or other materials into the bloodstream to stop the bleed
• Surgery to access the affected area of the GI tract to stop the bleeding

Moderate to mild GI bleeds may require upper or lower GI endoscopy, colonoscopy, or flexible sigmoidoscopy to identify the source of the bleed and stop it. A medical professional will inject medicines into the bleeding site or use heat, lasers, or a band or clip to close the affected blood vessels and stop the bleeding. 

You can lower your risk of developing a GI bleed by following your treatment plan for any underlying conditions associated with bleeding, such as peptic ulcers or IBD. Certain lifestyle habits can also help prevent certain types of GI bleeds, including: 

• Limit NSAID use: Use nonsteroidal anti-inflammatory medications (NSAIDs) such as Advil (ibuprofen) and Aleve (naproxen), sparingly and under the guidance of a healthcare provider. 
• Limit alcohol intake: Alcohol can trigger or worsen certain conditions associated with GI bleeding, including peptic ulcers and liver disease.
• Eat a fiber-rich diet: A nutritious, balanced diet with plenty of fiber-rich foods, including whole grains, fruits, and vegetables, supports your overall digestive health. 

An untreated or severe GI bleed can lead to complications, such as: 

• Hypovolemic shock: This life-threatening condition occurs when the body loses a large amount of blood. Significant blood loss requires emergency medical care, as it can quickly lead to organ failure and death. 
• Anemia: Chronic GI bleeds can lead to anemia, which occurs when the body lacks enough healthy red blood cells to carry oxygen to its tissues and organs. Anemia can cause fatigue, weakness, pale skin, shortness of breath, and dizziness.

A gastrointestinal (GI) bleed occurs when there is bleeding in the upper or lower digestive tract. All GI bleeds require medical treatment to stop the bleeding and address the underlying cause.

You can lower your risk of a GI bleed by following your treatment plan for any chronic conditions associated with GI bleeds, eating a healthy diet, and attending regular appointments with your healthcare provider.