Gastrointestinal (GI) bleeding is a serious symptom that occurs within your digestive tract. Your digestive tract consists of the following organs:

  • esophagus
  • stomach
  • small intestine, including the duodenum
  • large intestine or colon
  • rectum
  • anus

GI bleeding can occur in any of these organs. If bleeding occurs in your esophagus, stomach, or initial part of the small intestine (duodenum), it’s considered upper GI bleeding. Bleeding in the lower small intestine, large intestine, rectum, or anus is called lower GI bleeding.

The amount of bleeding you experience can range from a very small amount of blood to a life-threatening hemorrhage. In some cases, there may be so little bleeding, blood can only be discovered by testing the stool.

There are a few things that you can look for if you suspect that you might have GI or rectal bleeding. Your stool might become darker and sticky, like tar, if bleeding comes from the stomach or upper GI tract.

You may pass blood from your rectum during bowel movements, which could cause you to see some blood in your toilet or on your toilet tissue. This blood is usually bright red in color. Vomiting blood is another sign that there’s bleeding somewhere in your GI tract.

If you experience any of these symptoms, or if you have vomit that looks like coffee grounds, contact a doctor immediately.

When it’s an emergency: Symptoms of shock

GI bleeding could signal a life-threatening condition. Immediate medical treatment is essential. Also, seek treatment immediately if you experience any of the following symptoms:

Different parts of the digestive tract are affected by specific conditions. Bleeding in the GI tract is usually divided into upper GI tract or lower GI tract bleeding. There are various causes of bleeding in different regions.

Causes of upper GI bleeding

Upper GI bleeding has several causes, including:

  • Peptic ulcers. Peptic ulcers are a common cause of GI bleeding. These ulcers are open sores that develop in the lining of your stomach or duodenum. Taking non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (Advil), on a regular basis may increase your risk for peptic ulcers. You may also be at a higher risk if you take blood thinners. An infection from H. pylori bacteria can also cause peptic ulcers.
  • Tears in the veins in your esophagus. Enlarged veins in your esophagus can tear and bleed as a result of a condition called esophageal varices. You may be at a higher risk for this condition if you have portal hypertension, which often results from cirrhosis, a severe scarring of the liver.
  • Tears in the walls of your esophagus. This condition is known as Mallory-Weiss syndrome. This condition is often caused by severe or repeated vomiting.
  • Gastritis and duodenitis. Gastritis is inflammation in your stomach, while duodenitis is inflammation in your small intestine. Both are commonly caused by an infection from H. pylori bacteria, but they can also be caused by other factors, including overuse of NSAIDs or alcohol.
  • Foreign body ingestion. Swallowing something inedible can cause tears and bleeding in the upper GI tract.
  • Upper GI tumors. Tumors, such as those caused by esophageal cancer, stomach cancer, and cancer of the small intestine, can cause bleeding. Sometimes pancreatic tumors can also cause bleeding in the GI tract, depending on their location.
  • Angiodysplasia. Angiodysplasia causes enlarged blood vessels in the GI tract.

Causes of lower GI bleeding

Lower GI bleeding can be caused by:

  • Hemorrhoids. Hemorrhoids are another common cause of GI or rectal bleeding. A hemorrhoid is an enlarged vein in your rectum or anus. These enlarged veins can rupture and bleed, causing rectal bleeding. This condition may resolve on its own or with minimal therapies. However, a doctor may decide to perform a colonoscopy if the bleeding seems suspicious for other more serious GI issues.
  • Anal fissure. An anal fissure may also cause lower GI bleeding. This is a tear in the muscular ring that forms the anal sphincter. It’s usually caused by constipation or hard stools.
  • Diverticulosis. This is a chronic condition where the wall of the colon protrudes at the location of vessels and over time can cause the vessels to rupture and bleed. Bleeding due to diverticulosis can often resolve on its own without invasive therapies. A doctor may perform a colonoscopy to rule out other, more serious causes of lower GI bleeding, such as cancer.
  • Colon cancer. Colon cancer starts in your colon or rectum.
  • Angiodysplasia. This condition causes enlarged blood vessels in the digestive tract.
  • Colitis. One of the most common causes of lower GI bleeding is colitis, which occurs when your colon becomes inflamed.

Colitis has several causes, including:

If you believe you may have GI bleeding, it’s important to talk with a doctor. If the bleeding is serious, you may need emergency care to determine the cause and treat the condition. If your bleeding is serious, you may be admitted to the hospital.

Testing can be useful, not only in diagnosing GI bleeding but also for treating it.

Special scopes with cameras and laser attachments, along with medications, can be used to stop the bleeding. In addition, the doctor can use tools alongside scopes to apply clips to the bleeding vessels to stop the bleeding.

If hemorrhoids are the cause of your bleeding, over-the-counter (OTC) treatments might work for you. If you find that OTC remedies don’t work, a doctor might use a heat treatment to shrink your hemorrhoids, or in severe cases, a surgical procedure to remove them.

Antibiotics can usually treat infections.

Diagnosis of the underlying cause of your GI bleeding will usually start with a doctor asking about your symptoms and medical history. The doctor may also request a stool sample to check for the presence of blood along with other tests to check for signs of anemia.

Diagnosing upper GI bleeding

To diagnose upper GI bleeding and figure out what’s causing it, a doctor may perform the following tests:

  • Endoscopy. Upper GI bleeding is most commonly diagnosed with an endoscopy. This procedure involves the use of a small camera located atop a long, flexible endoscopic tube the doctor places down your throat. The scope is then passed through your upper GI tract. The camera allows the doctor to see inside your GI tract and potentially locate the source of your bleeding.
  • Enteroscopy. This procedure is performed if the cause of your bleeding isn’t found during an endoscopy. An enteroscopy is similar to an endoscopy, except there’s usually a balloon attached to the camera-tipped tube. When inflated, this balloon allows your doctor to open up the intestine and see inside.

Diagnosing lower GI bleeding

A doctor may perform the following tests to determine the cause of lower GI bleeding:

  • Colonoscopy. During a colonoscopy, your doctor will insert a small, flexible tube into your rectum. A camera is attached to the tube so your doctor can view the entire length of your colon. Air moves through the tube to provide a better view.
  • Biopsy. During the colonoscopy, the doctor may take a biopsy for additional testing.
  • X-ray. You may also undergo a scan to locate your GI bleeding. A harmless radioactive tracer will be injected into your veins. The tracer will light up on an X-ray so your doctor can see where you’re bleeding.
  • CT angiography. A CT scan is an imaging test that can help the doctor locate GI bleeding in the abdomen and pelvis. It often shows more detail than an X-ray.
  • Capsule endoscopy. If your doctor can’t find the source of your bleeding with an endoscopy or a GI bleeding scan, they may perform a capsule endoscopy. Your doctor will have you swallow a pill that contains a small camera that will take pictures of your bowel to find the source of your bleeding.
  • RBC nuclear scan. In this exam, a doctor injects a harmless radioactive tracer to track your red blood cells. This can show how the cells perform in your body.

Bleeding in the digestive tract may be a sign of a serious and life-threatening condition. It’s important to seek timely medical attention.

Untreated GI bleeding may result in serious complications, including:

  • respiratory distress
  • heart attack
  • infection
  • shock
  • death

GI bleeding is a serious symptom that requires prompt medical treatment. From tears in the organs in the digestive tract to inflammatory conditions, these causes often require examination by a doctor to diagnose and treat.

Left untreated, they may result in serious complications, including heart attack and shock.

Some causes of bleeding, like hemorrhoids, may be treatable with OTC medications. It’s best to make an appointment with a doctor to determine the cause of your bleeding.