Gastrointestinal Bleeding

Epidemiology and Etiology

Epidemiology

• Upper gastrointestinal bleeding (UGIB):
  • Incidence of about 100 per 100,000 adults per year
  • Twice as common in men
  • Increased risk with age (> 60 years)
• Lower gastrointestinal bleeding (LGIB):
  • Incidence of about 20.5 per 100,000 adults per year
  • Increased risk with age (200-fold increase in the 3rd to 9th decades)
  • Somewhat more common in men
• Risk factors:
  • Helicobacter pylori infection
  • Nonsteroidal anti-inflammatory drugs (NSAIDs)
  • Alcohol use
  • Cirrhosis
  • Vascular disease

Etiology

Upper gastrointestinal bleed (proximal to the ligament of Treitz): 

• Esophagus
  • Esophageal varices
  • Esophagitis: infection or inflammation in the esophagus 
  • Esophageal cancer
  • Mallory-Weiss tear: a tear in the esophageal lining due to forceful vomiting
• Stomach
  • Gastric ulcer
  • Erosive gastritis
  • Gastric antral vascular ectasia (GAVE): dilated small blood vessels in the pyloric antrum (uncommon)
  • Portal hypertensive gastropathy
  • Dieulafoy lesion: large, tortuous vessel that can erode and bleed
  • Angiodysplasia: abnormal collection of blood vessels
• Duodenum
  • Duodenal ulcer
  • Angiodysplasia
  • Aortoenteric fistula (rare)
• Gastric and duodenal ulcers are the most common causes.

Lower GIB (distal to the ligament of Treitz):

• Diverticular disease
  • Diverticulosis: sac-like protrusion of the colonic wall (common)
  • Diverticulitis: less commonly associated with GI bleed
  • Meckel’s diverticulum: congenital outpouching in the ileum
• Vascular disease
  • Angiodysplasia
  • Ischemia (e.g., mesenteric ischemia, ischemic colitis)
  • Hemorrhoids: venous structures of the anorectum that engorge, prolapse, and bleed
• Trauma
  • Anal fissure: a small tear in the anal mucosa
• Neoplasm
  • Colon polyp
  • Colorectal cancer
• Inflammatory disease 
  • Infectious colitis
  • Ulcerative colitis and Crohn’s disease: autoimmune inflammatory bowel diseases that cause inflammation and ulcers 
• Iatrogenic
  • After biopsy or polypectomy
  • Radiation colitis: radiation-induced inflammation in the colon
  • Aortoenteric fistula (rare, but serious)

Clinical Presentation

Clinical manifestations

• Patients with occult bleeding may be asymptomatic.
• Symptoms of anemia:
  • Fatigue, weakness
  • Dyspnea
  • Pallor
  • Lightheadedness
  • Syncope
• Abdominal pain or heartburn → ulcers, gastritis, ischemia
• Coffee-ground emesis → UGIB
• Hematemesis → UGIB
• Melena (black, tarry stool)
• Hematochezia (bright-red blood in stools) 
  • Usually seen in LGIB
  • Can be from brisk, large-volume UGIB
• Weight loss → malignancy

Physical exam

• Patients with mild or occult bleeding may not have significant findings.
• Evidence of hemodynamic instability:
  • Tachycardia
  • Hypotension
  • Altered mental status
• Orthostatic hypotension: seen with acute blood loss of ≥ 2 units
• Pale skin color and conjunctiva
• Some may have abdominal tenderness (e.g., ischemia).
• Rectal exam:
  • Black or bloody stools
  • Normal, brown stool may be seen in occult bleeding
  • Hemorrhoids
  • Anal fissure
  • Rectal mass
• Evaluate for signs of chronic liver disease:
  • Spider angiomata
  • Splenomegaly
  • Abdominal distension and ascites
  • Asterixis

Diagnosis

Diagnosis and management of GIB tend to go hand-in-hand and will vary depending on the hemodynamic stability of the patient.

Laboratory evaluations

• Complete blood count → anemia from blood loss
  • Hemoglobin may initially be normal in acute bleeds.
  • Potential thrombocytopenia may be seen in cirrhosis.
• Fecal occult blood testing → detect occult bleeding
• Coagulation factors → coagulopathy, which may need reversal
• Liver function tests → underlying liver disease
• Basic metabolic panel → ↑ BUN (blood urea nitrogen) may signal upper GIB
• Iron, ferritin → iron deficiency

Imaging

• Computed tomography with angiography (CTA)
  • Bleeding rate of at least 0.3–0.5 mL/min required for detection
  • Utilizes intravenous (IV) contrast to localize hemorrhage
• Radionuclide imaging
  • Bleeding rate of at least 0.1–0.5 mL/min required for detection
  • Most sensitive radiographic test 
  • Radioisotope is injected into the bloodstream to reveal sites of extravasation.

Procedures

• Esophagoduodenoscopy (EGD)
  • Modality of choice in UGIB
  • Visualize the site of hemorrhage within the esophagus, stomach, or duodenum.
  • Collect pathology specimens.
• Colonoscopy
  • Modality of choice in LGIB
  • Visualize the site of hemorrhage within the large intestine and terminal ileum.
  • Collect pathology specimens.
  • Colon preparation is required.
• Capsule endoscopy
  • Provides imaging of the small intestine
  • Patient swallows a wireless camera, which takes pictures along the digestive tract.
  • Most often used for continued or intermittent bleeding when EGD and colonoscopy are unremarkable
• Angiography
  • Bleeding rate of at least 0.5–1 mL/min is required for detection.
  • Reserved for patients who cannot undergo endoscopy due to hemodynamic instability

Management

Initial steps

Assess the patient’s hemodynamics and stabilize:

• Protect the patient’s airway:
  • Patient may need intubation for severe hematemesis
  • Prevent aspiration
• Obtain adequate IV access: 2 large-gauge peripheral IVs and/or central line
• IV fluid resuscitation
• Send a blood type and screen evaluation.
• Blood transfusion

Medications

• Proton pump inhibitors (pantoprazole)
• Octreotide 
  • Somatostatin analog, which causes splanchnic vasoconstriction
  • Used for esophageal bleeding

Interventions

• Around 80% will stop bleeding without intervention.
• EGD and colonoscopy
  • Injection of epinephrine around bleeding point 
  • Thermal hemostasis (electrocoagulation)
  • Endoclips
• Angiography 
  • Vasoconstriction via vasopressin 
  • Embolization
  • Procedure runs the risk of bowel ischemia or infarction.
• Balloon tamponade
  • Used for esophageal varices
  • Tube is inserted into the esophagus, and balloon is inflated.
  • Provides short-term hemostasis until definitive treatment can be arranged.
• Surgery 
  • Considered when bleeding cannot be contained through the above interventions (rare)
  • Localization of the source is important before pursuing surgery.

Special considerations

• Patients with cirrhosis and variceal bleeding should have antibiotic prophylaxis to prevent spontaneous bacterial peritonitis.
• Reverse any anticoagulation.
• Hold antihypertensive medications.

Differential Diagnosis

• Epistaxis: bleeding from the nasal mucosa. Blood may be swallowed and then vomited (appearing like hematemesis), or go through the GI tract and present in the stool. Careful history and examination of the nasal mucosa can identify the cause. Most nosebleeds are benign and self-limited, but may require oxymetazoline nasal spray, cauterization, or nasal packing. 
• Food and medication: Some foods or medications can cause false positive fecal occult testing, including beets, broccoli, cantaloupe, carrots, cauliflower, cucumbers, grapefruit, red meat, and iron pills. Bismuth can cause black, spearing stools that are fecal occult negative. Patients should avoid these foods and medications 48 hours prior to fecal occult blood testing. 
• Hemoptysis: coughing up blood from the airway or pulmonary structures. Causes include lung cancer, infections, pulmonary edema, and vasculitides. Testing the pH of the fluids may be helpful, since an alkaline pH is indicative of airway bleeding and GI tract bleeding will be acidic. Imaging of the chest to look for underlying lung pathology is also useful. Treatment includes airway protection and identification and treatment of the underlying problem.