Difference Between Upper and Lower GI Bleed

Gastrointestinal (GI) bleeding is a serious condition where blood loss occurs from the digestive tract. While GI bleeds can occur anywhere from the mouth to the anus, they are typically categorized into two types based on their location: upper gastrointestinal (UGI) bleeding and lower gastrointestinal (LGI) bleeding.Upper GI bleeding is often associated with vomiting blood or melena and commonly results from peptic ulcers, esophageal varices, or gastritis. On the other hand, lower GI bleeding presents as hematochezia and is often caused by diverticular disease, hemorrhoids, or colorectal cancer.Prompt identification and appropriate treatment are crucial to prevent severe complications, such as shock, organ failure, or death. 

Key differences between upper GI bleed and lower GI bleed:

Best Scrubs Collection

Understanding the GI Tract

The GI tract is a continuous tube extending from the mouth to the anus. Anatomically, the division between the upper and lower gastrointestinal tract is marked by the ligament of Treitz, a thin muscle that supports the duodenojejunal junction.

• Upper GI tract: Consists of the esophagus, stomach, and duodenum (first part of the small intestine).
• Lower GI tract: Includes the small intestine (beyond the duodenum), large intestine (colon), rectum, and anus.

The source of bleeding above the ligament of Treitz is considered upper GI bleeding, while bleeding below this point is classified as lower GI bleeding.

Upper GI Bleeding

Upper GI bleeds arise from the esophagus, stomach, or duodenum and can be caused by several conditions

Causes of Upper GI Bleeding

Peptic Ulcer Disease (PUD):

• The most common cause of UGI bleeding.
• Ulcers, typically in the stomach or duodenum, develop due to the erosion of the lining caused by excess stomach acid, infection by Helicobacter pylori, or prolonged use of NSAIDs (nonsteroidal anti-inflammatory drugs).

Esophageal Varices

• Dilated veins in the lower esophagus or upper stomach, often due to portal hypertension (commonly related to cirrhosis). These varices can rupture and cause life-threatening bleeding.

Mallory-Weiss Tears

• Lacerations in the mucosal lining near the junction of the esophagus and stomach, often caused by severe vomiting, retching, or coughing, leading to bleeding.

Gastritisand Esophagitis

• Inflammation of the stomach or esophagus due to factors like infection, alcohol consumption, or prolonged NSAID use. This inflammation can erode the mucosal lining and cause bleeding.

Gastric Cancer

• Malignancies in the stomach may also lead to upper GI bleeding, although this is less common compared to ulcers and varices.

Symptoms

• Hematemesis: Vomiting blood is a hallmark of UGI bleeding. The vomited blood may appear bright red (indicating active bleeding) or resemble coffee grounds (partially digested blood).
• Melena: Black, tarry stools result from the partial digestion of blood as it passes through the intestines, typically seen in UGI bleeding.
• Dizziness or Fainting: Due to significant blood loss, patients may experience symptoms of shock, such as lightheadedness, fainting, or confusion.
• Abdominal Pain: Depending on the underlying cause (e.g., peptic ulcer), the patient may also experience epigastric pain.

Diagnosing Upper GI Bleeds

• Endoscopy (EGD): The gold standard for evaluating UGI bleeding. This procedure involves inserting a flexible camera into the esophagus, stomach, and duodenum to directly visualize the source of bleeding. If an ulcer or variceal bleed is identified, it can often be treated during the procedure.
• Nasogastric Tube Aspiration: In some cases, a nasogastric tube can be used to assess the presence of blood in the stomach.
• Blood Tests: Assessing for anemia, coagulation abnormalities, and other signs of blood loss.

Treatment of Upper GI Bleeds

• Endoscopic Intervention: If endoscopy reveals an ulcer, variceal bleed, or other causes, the physician may use techniques like band ligation, sclerotherapy, or cauterization to stop the bleeding.
• Medications: Proton pump inhibitors (PPIs) are commonly used to reduce stomach acid and promote ulcer healing. In cases of variceal bleeding, medications like octreotide may be given to reduce portal hypertension.
• Surgery: In severe cases where bleeding cannot be controlled endoscopically, surgery may be necessary to repair the source of the bleed.

Explore All Women's Scrub

Lower GI Bleeding

Lower GI bleeds originate from the small intestine (beyond the duodenum), colon, rectum, or anus. 

Causes of Lower GI Bleeding

Diverticular Disease

Diverticulosis involves the formation of small pouches (diverticula) in the colon wall, which can erode and bleed. It’s one of the most frequent causes of significant LGI bleeding, especially in older adults.

Hemorrhoids

Swollen veins in the rectum or anus can rupture, leading to bright red blood in the stool. While hemorrhoids can cause noticeable bleeding, they are usually not life-threatening.

Colonic Polyps

Benign growths in the colon that can bleed. While polyps themselves are not cancerous, they may be a precursor to colorectal cancer.

Colorectal Cancer

Tumors in the colon or rectum can ulcerate and bleed, often causing chronic blood loss, leading to anemia. Colorectal cancer is a more common cause of LGI bleeding in older adults.

Inflammatory Bowel Disease (IBD):

Conditions like Crohn’s disease and ulcerative colitis cause chronic inflammation of the intestines and can result in both acute and chronic GI bleeding.

Symptoms

• Hematochezia: Passage of bright red blood or maroon stools is commonly associated with LGI bleeding, as the blood hasn’t been digested. This is a key differentiator from upper GI bleeding.
• Cramping or Abdominal Pain: Particularly in cases of diverticular disease or IBD, patients may experience abdominal discomfort.
• Weakness or Fatigue: Chronic LGI bleeding, such as from colorectal cancer or polyps, can lead to iron deficiency anemia, causing fatigue or pallor.

Diagnosing Lower GI Bleeds

• Colonoscopy: Similar to endoscopy, this procedure is used to visualize the colon and rectum. It is the primary tool for diagnosing LGI bleeding sources, such as diverticula, polyps, or tumors.
• CT Angiography: A non-invasive imaging test used to identify active bleeding in the GI tract, especially when colonoscopy isn’t feasible or when bleeding is too rapid.
• Capsule Endoscopy: A pill-sized camera can be swallowed to evaluate bleeding sources in the small intestine, which may not be accessible by traditional endoscopy or colonoscopy.

Treatment of Lower GI Bleeds

• Endoscopic Therapy: Colonoscopy may allow for polyp removal, treatment of bleeding diverticula, or cauterization of bleeding vessels.
• Interventional Radiology: For persistent or severe bleeding, angiographic embolization can be used to block the bleeding vessel.
• Surgery: In cases of malignancy or diverticular disease that can’t be managed with less invasive methods, surgical resection may be necessary.

Shop the Best Lab Coats from Here!