Gastrointestinal bleeding

Diagnostic approach

• ABCDE survey
• Targeted clinical evaluation
• 12-lead ECG
• CBC: Initial Hb/Hct may not reflect the degree of acute hemorrhage.
• BMP
• Lactate
• Coagulation panel
• Type and screen, crossmatching
• Stable patients with hematemesis: Consult GI for EGD.
• Unstable patients with hematemesis: Consider mesenteric angio if EGD is not possible.
• Stable patients with hematochezia: Consult GI for colonoscopy after standard bowel prep.
• Unstable patients with hematochezia: CTA

Red flag features

• Resting SBP ≤ 90 mm Hg and/or HR ≥ 120/minute
• Dry MM, oliguria, ↓ JVP
• Cold extremities, pallor, cyanosis, cap refill > 2 seconds
• ECG suggesting concomitant ACS

Management checklist

• Two large-bore peripheral IVs
• NPO
• Consider intubation for airway protection (e.g., for AMS or severe ongoing hematemesis).
• Start IV fluids for unstable patients.
• Transfuse pRBCs if Hb is ≤ 7 g/dL; consider a higher threshold for unstable patients.
• Consult GI and/or IR.
• Variceal bleed: ceftriaxone PLUS octreotide
• Consider antithrombotic reversal.
• Consider erythromycin before EGD.
• Do not delay endoscopy in patients with INR ≤ 2.5.

Life-threatening causes

• Variceal bleeding
• Mallory-Weiss syndrome
• Boerhaave syndrome
• Arteriovenous malformation
• Colorectal varices
• Ischemic colitis

Gastrointestinal (GI) bleeding can originate from the upper GI tract (proximal to the ligament of Treitz), small bowel, or lower GI tract (distal to the ileocecal valve). Overt GI bleeding is visible in the form of hematemesis, melena, and/or hematochezia, whereas occult GI bleeding typically manifests with nonspecific symptoms due to iron deficiency anemia. Common causes include esophageal variceal hemorrhage, bleeding peptic ulcer, diverticular bleeding, hemorrhoids, and malignancy. Esophagogastroduodenoscopy (EGD) and/or colonoscopy are the preferred initial tests for stable patients with suspected GI bleeding. Initial management of overt GI bleeding focuses on hemodynamic resuscitation, and, if feasible, endoscopic identification of the source, followed by measures to control bleeding (endoscopically, surgically, or via angioembolization). Sigmoidoscopy is the appropriate initial investigation in patients aged < 40 years with intermittent scant hematochezia and no features of underlying malignancy or inflammatory bowel disease (IBD).

• Upper gastrointestinal bleeding (UGIB): gastrointestinal bleeding from the esophagus, stomach, or duodenum (proximal to the ligament of Treitz) ^[1]
• Lower gastrointestinal bleeding (LGIB): gastrointestinal bleeding from the colon or rectum ^[2]
• Small bowel bleeding: GI bleeding from a source between the ligament of Treitz and the ileocecal valve ^[1]
• Overt GI bleeding: GI bleeding that is visible in the form of hematemesis, melena, or hematochezia (including intermittent scant hematochezia) ^[1]
• Obscure gastrointestinal bleeding: Overt GI bleeding from an undetermined source that persists or recurs after a negative diagnostic evaluation

• UGIB: ∼ 70–80% of all GI hemorrhages ^[3]
• LGIB: ∼ 20–30% of all GI hemorrhages ^[4]
• Small bowel bleeding: ∼ 5–10 % of all patients presenting with GI bleeding ^[5]

Epidemiological data refers to the US, unless otherwise specified.

Common causes of GI bleeding

Risk factors for GI bleeding ^[2][6]

• Any GI bleeding
  • NSAID use
  • Antithrombotic use, e.g., antiplatelet therapy, anticoagulants
  • History of prior GI bleeding
  • Older age
• Upper GI bleeding
  • H. pylori infection
  • Renal failure, especially in the first year of hemodialysis

Features of overt GI bleeding ^[10]

• Hematemesis: vomiting blood, which can vary in color from bright red to brown and may resemble coffee grounds, depending on the cause
  • Most commonly caused by UGIB
  • Less commonly caused by bleeding from the upper respiratory tract, e.g., brisk epistaxis
• Melena: black, tarry stool with a strong offensive odor
  • Most commonly caused by UGIB
  • Less commonly caused by bleeding from the small bowel or the proximal colon
• Hematochezia: passage of blood through the anus with or without stool
  • Most commonly caused by LGIB
    • Maroon, jellylike traces of blood in stool indicate colonic bleeding.
    • Streaks of fresh blood on stool indicate rectal bleeding.
  • Less commonly caused by severe UGIB

Melena and hematochezia can be caused by UGIB, small bowel bleeding, and LGIB. ^[2]

Accompanying signs and symptoms

• Signs of acute, severe bleeding
  • Clinical features of shock
    • Tachycardia
    • Hypotension
    • Altered mental status
  • Syncope
• Clinical features of anemia
• Features of the underlying cause of GI bleed ^[2]
  • Signs of cirrhosis
  • Abdominal pain, nausea and/or vomiting
  • Unintentional weight loss
  • Constipation and/or painful defecation ^[11]

Unexplained iron deficiency anemia (especially in men or postmenopausal patients) should raise suspicion for GI bleeding.

For severe GI bleeding, perform initial evaluation concurrently with stabilization and initial management of overt GI bleeding.

Clinical evaluation

• Focused medical history
  • Current symptoms, including features of overt GI bleeding and accompanying symptoms ^[2]
  • History of GI bleeding
  • History of GI surgery or recent endoscopic procedure
  • History of associated conditions, e.g., cirrhosis ^[2]
  • Risk factors for PUD
  • Medication history, e.g., NSAIDs, antithrombotic agents, beta blockers ^[2][10]
• Focused physical examination
  • Vital signs to assess for massive hemorrhage ^[2][10]
    • Resting SBP ≤ 90 mm Hg and/or HR ≥ 120/min ^[10]
    • Orthostatic hypotension ^[10]
  • Abdominal examination, including DRE to assess for: ^[2][9][11]
    • Melena, hematochezia
    • Hemorrhoids, anal fissures, anal masses
  • Evaluation for signs of hypovolemia ^[2]
  • Evaluation for signs of portal hypertension ^[11]
• ECG: Obtain in patients aged > 35 years with suspected or confirmed UGIB to assess for concomitant acute coronary syndrome. ^[11]

Laboratory studies ^[9][10][11]

• CBC
  • Normal or ↓ Hb and Hct
  • Platelets to assess for thrombocytopenia
• BMP: ↑ BUN/Cr ratio suggests UGIB. ^[10][12][13]
• Lactate: Initial levels > 2.5 mmol/dL are associated with adverse outcomes. ^[11]
• Albumin ^[9]
• Coagulation panel
• Pretransfusion testing: type and screen, crossmatching

An elevated BUN/creatinine ratio in a patient with hematochezia suggests severe UGIB. ^[14][15]

Do not delay initial management for diagnostic testing in unstable patients.

Approach

• Obtain intravenous access for possible fluid resuscitation and blood transfusion.
  • Insert two large-bore peripheral IV catheters.
  • Consider a central line if reliable large-bore peripheral venous access is not possible.
• Order NPO status.
• Start initial management based on hemodynamic stability, and treatment of the underlying cause, if known.
• Manage antithrombotic medications on a case-by-case basis.
• Consider empiric pharmacotherapeutic treatment for UGIB.

Unstable patients

• Follow an ABCDE approach.
• Consider intubation to protect the airway (e.g., in patients with altered mental state or severe ongoing hematemesis); see “High-risk conditions for intubation.” ^[10]
• Start immediate hemodynamic support and management of hemorrhagic shock.
  • IV fluid resuscitation with crystalloids ^[8]
  • Blood transfusion
    • Exceptions to restrictive transfusion strategy may be made in patients with hypotension. ^[1][16]
    • Massive transfusion may be considered in patients with massive blood loss. ^[1][16]
• Consider anticoagulation reversal.
• Urgently consult gastroenterology, surgery, and/or interventional radiology for patients with ongoing bleeding and refractory hemodynamic instability.

Exercise caution with volume resuscitation in the absence of massive ongoing bleeding or hemorrhagic shock, especially if the source of hemorrhage is inadequately controlled. Aggressive administration of crystalloids and blood products can increase the risk of rebleeding and death. ^[14][17]

Stable patients

• Perform a risk assessment in GI bleeding to guide further disposition and management.
• Follow a restrictive transfusion strategy. ^[9]
  • Packed red blood cell transfusion if Hb < 7 g/dL ^[1][2][18]
  • A higher threshold (e.g., Hb < 8 g/dL) may be considered in patients with preexisting cardiovascular disease or delays in endoscopy. ^[1][9][18]

Patients taking antithrombotic agents ^[2][19][20]

High-quality evidence to guide antithrombotic therapy in GI bleeding is lacking. Follow local protocols where available.

Oral anticoagulants

• Withhold oral anticoagulants in patients hospitalized with significant bleeding. ^[2]
• Consider anticoagulant reversal based on hemodynamic stability, bleeding severity, laboratory findings, e.g., INR. ^[2]
  • Vitamin K antagonists: Consider reversal with PCC for life-threatening GI bleeding with INR significantly above the therapeutic range or if massive blood transfusion is not feasible. ^[2][20]
  • DOACs: Consider targeted DOAC reversal for life-threatening GI bleeding and refractory hemodynamic instability if DOAC was taken within 24 hours. ^[2][20]
• Resume anticoagulants after cessation of LGIB. ^[2]

Most patients with LGIB on oral anticoagulants will not require reversal. ^[2]

Do not delay endoscopy in patients with moderately elevated INRs (e.g., ≤ 2.5). ^[2]

Antiplatelet agents ^[2][20]

• Review the indications for therapy with a specialist before withholding antiplatelet agents. ^[2]
  • Aspirin
    • Primary prevention of ASCVD: Withhold and consider permanently stopping.
    • Patients with ASCVD: Continue if possible; resume within 24 hours of endoscopic hemostasis if aspirin has been withheld. ^[20]
  • Nonaspirin antiplatelet agents
    • Withhold during hospitalization if possible.
    • Individualize approach for patients who underwent cardiovascular stenting within the last year.
• Transfuse platelets only in patients with severe thrombocytopenia (threshold of < 30,000/mm³ or < 50,000/mm³ if endoscopic hemostasis is planned) or those with other indications for platelet transfusions (e.g., massive transfusion). ^[20]

Empiric pharmacotherapeutic treatment for UGIB

• Prior to EGD:
  • Consider erythromycin; (off-label) to improve visualization during EGD. ^[1][7]
  • The benefit of preprocedural PPIs is unclear. ^[1][7][18]
• If esophageal variceal bleeding is suspected:
  • Start vasoactive therapy with octreotide; (off-label) or vasopressin. ^[17]
  • Start antibiotic prophylaxis with ceftriaxone; (off-label) . ^[21]
  • See “Management of esophageal variceal hemorrhage” for further details.

Do not delay hemostatic interventions and definitive diagnosis for pharmacological treatment.

Diagnostic approach to overt GI bleeding

Perform an initial evaluation of GI bleeding to determine the likelihood of UGIB vs. LGIB.

Approach to suspected UGIB ^[7][17]

• Hemodynamically unstable
  • Initial study: EGD
  • Consider mesenteric angiography if EGD is not possible or nondiagnostic. ^[22][23]
• Hemodynamically stable
  • Initial study: EGD ^[8]
  • If EGD is nondiagnostic, consider one of the following:
    • Colonoscopy after bowel prep in patients with melena ^[8]
    • CTA ^[24]
  • If the workup remains negative, consider evaluation for small bowel bleeding. ^[22]

If suspicion for UGIB is high in a patient with hematochezia and hemodynamic instability, EGD is the preferred initial study to rule out a brisk proximal source of bleeding. ^[2]

Approach to suspected LGIB ^[2][9]

• Hemodynamically unstable
  • Initial study: CTA ^[2][9][24]
  • If CTA identifies the source of bleeding, proceed to either:
    • Catheter angiography with angioembolization
    • Colonoscopy to attempt endoscopic hemostasis ^[2]
• Hemodynamically stable
  • Initial study: nonemergency colonoscopy after bowel preparation ^[2][9]
  • Consider CTA for patients who cannot tolerate bowel preparation or if there is high suspicion for active bleeding. ^[24]
  • Tagged-RBC scintigraphy may be ordered for patients with ongoing LGIB that can not be localized with colonoscopy and CTA. ^[24]
  • If the workup remains negative, consider evaluation for small bowel bleeding.

Approach to suspected small bowel bleeding ^[5][22]

Evaluate for small bowel bleeding in patients with obscure GI bleeding.

• Repeat endoscopy first.
• If not already done, obtain CTA in hemodynamically unstable patients. ^[22][24]
• Video capsule endoscopy is preferred in hemodynamically stable patients with negative EGD and colonoscopy. ^[22]
• Consider further investigations as necessary, e.g.:
  • Advanced endoscopic evaluation: push enteroscopy, double balloon enteroscopy
  • Radiographic evaluation: CT enterography, tagged RBC scintigraphy, Meckel scan

Endoscopy

Endoscopic procedures (e.g., EGD and colonoscopy) allow for bleeding source identification, diagnostic biopsies, and/or endoscopic hemostasis.

EGD ^[1][7][17]

• Timing
  • Most patients: within 24 hours of presentation ^[1][7]
  • Suspected esophageal variceal bleeding: within 12 hours of presentation ^[17]
• Preparation
  • Consider intubation prior to endoscopy if there is a high risk of aspiration. ^[17]
  • Consider erythromycin (off-label) to improve visualization. ^[1]
• Further management: If there are signs of active bleeding or recent hemorrhage, proceed to endoscopic hemostasis.

Colonoscopy ^[2][8]

• Timing
  • Most patients: at the next available opportunity after bowel preparation (nonemergency) ^[2][9]
  • Urgent colonoscopy within 24 hours of presentation may be considered in patients who are very likely to require endoscopic hemostasis, e.g., those with:
    • Active source of bleeding already confirmed on CTA ^[2]
    • Postpolypectomy bleeding ^[2]
• Preparation: Follow local bowel preparation protocols where available.
  • Consider rapid bowel preparation with a polyethylene glycol-based solution for patients undergoing urgent colonoscopy. ^[2]
  • Standard bowel preparation strategies, e.g., split-dose or low-dose bowel preparation, are appropriate for most patients. ^[2]
• Further management: If active bleeding or stigmata of recent hemorrhage are identified, proceed to endoscopic hemostasis. ^[2]

Colonoscopy without bowel preparation is not recommended. Sigmoidoscopy is only an option if the source is known to be in the distal colon or rectal area. ^[2]

Mesenteric angiography ^[23][25]

• Indications
  • Consider as initial test for:
    • Suspected active LGIB in hemodynamically unstable patients ^[2][8]
    • Suspected active UGIB if endoscopy is contraindicated ^[25]
  • Further workup of ongoing GI bleeding and negative endoscopy ^[22][25]
• Modalities
  • CT angiography (CTA): allows for rapid source localization to help target hemostatic interventions
  • Catheter angiography: dual diagnostic and therapeutic procedure when combined with angioembolization

Nasogastric aspiration

• Not routinely recommended
• Previously used to assess for UGIB in patients with hematochezia and a moderate pretest probability for UGIB

Endoscopic hemostasis ^[2][7]

• Indication: : preferred intervention for most patients with ongoing bleeding or signs of recent bleeding on endoscopy, e.g., ulcer with high-risk stigmata, angiodysplasia
• Techniques
  • Thermal coagulation (e.g., electrocauterization, argon plasma coagulation)
  • Clip placement
  • Band ligation
  • Injection with epinephrine solution
  • Topical sealants (e.g., hemostatic spray or powder)
  • Polypectomy in case of bleeding polyp

Interventional radiology (catheter angiography) ^[8][18][25]

• Indications
  • Ongoing severe LGIB in patients with hemodynamic instability refractory to resuscitation ^[8]
  • Identification of an arterial source of UGIB on endoscopy ^[25]
  • Consider in patients with rebleeding or ongoing bleeding despite endoscopic hemostasis ^[8][23]
• Techniques
  • Angioembolization (e.g., microcoils, gel foam, polyvinyl alcohol particles): preferred if feasible
  • Intraarterial vasopressin: if the source of bleeding is diffuse

Surgical hemostasis ^[8][18][23]

• May be considered in patients with ongoing GI bleeding only in the following scenarios:
  • All other therapeutic options have failed.
  • Refractory hemodynamic instability
• Techniques
  • Surgical ligation of bleeding vessels
  • Excision of susceptible mucosa, e.g., Dieulafoy lesion
  • Segmental bowel resection ^[8]

CTA before surgery can help to plan a targeted intervention and reduce perioperative risk. ^[2]

Patient disposition should be determined by multiple factors, including clinical judgment, risk stratification tools, individual patient characteristics (e.g., age, functional status, social support system), and access to medical care in the outpatient setting. ^[1][7][8]

Monitoring ^[10]

• Clinical: serial vital signs and monitoring for signs of hypovolemic shock
• Laboratory: serial CBC, coagulation screen, BMP ^[10]
• Cardiovascular
  • Continuous cardiac monitoring for patients with active bleeding
  • Serial ECG for patients with CAD

Initial disposition

• Outpatient management ^{[2][8] [1][7]}
  • Patients with low-risk LGIB may be considered for outpatient management, e.g., those with: ^[8]
    • Occult GI bleeding without severe anemia ^[8]
    • Intermittent scant hematochezia ^[8]
    • Recent high-quality colonoscopy ^[2]
  • Consider discharge after observation for clinically stable patients with all of the following: ^[2]
    • Low scores on risk stratification tools, e.g., Glasgow-Blatchford bleeding score ≤ 1 or Oakland score ≤ 8 ^[1][2][9]
    • No ongoing bleeding ^[2][9]
  • Advise early follow-up for outpatient diagnostic evaluation and management. ^[2]
• Inpatient admission: patients who do not meet the criteria for outpatient management
• ICU admission
  • Patients with evidence of severe, ongoing hemorrhage or hypovolemic shock ^[7][8]
  • Esophageal variceal bleeding ^[17]

Most patients with LGIB, normal vital signs, and no significant anemia can be managed on an outpatient basis.

Post endoscopy disposition

• Observation and discharge
  • May be considered for hemodynamically stable patients without ongoing bleeding and with low risk for recurrent bleeding ^[7]
  • Advise follow-up within 24 hours (earlier if symptoms recur) for further diagnostic evaluation and long-term management as needed.
• Inpatient management: patients with any endoscopic findings that are associated with a risk of rebleeding

Risk assessment in GI bleeding ^[1][2][9]

• Risk assessment tools estimate the need for medical intervention as well as the risks of rebleeding and mortality.
• Used in conjunction with clinical judgment to guide patient disposition
• Low-risk patients identified by these assessments may be appropriate candidates for outpatient management.
• Recommended tools
  • Glasgow-Blatchford bleeding score (UGIB) ^[7][18]
  • Oakland score (LGIB) ^[2][26][27]

UGIB risk assessment

LGIB risk assessment

Risk assessment scores should be used to guide but never replace clinical judgment.

Occult GI bleeding

• Definition: GI bleeding that is not visible and can only be detected by fecal occult blood tests or seen on microscopy
• Etiology
  • Most commonly caused by a source in the lower GI tract
  • Less commonly caused by sources in the upper GI tract, e.g., PUD, esophagitis. ^[8]
• Diagnostics
  • Fecal occult blood test (FOBT)
  • If FOBT is positive, obtain CBC ± iron studies and nonemergency colonoscopy. ^[8]
    • Consider EGD if colonoscopy is normal, especially if signs of or risk factors for UGIB are present. ^[8]
    • If endoscopy is normal despite positive FOBT and persistent anemia, consider small bowel evaluation. ^[8]
• Management
  • Identify and treat the underlying cause.
  • Correct anemia (see “Treatment of iron deficiency anemia”).

Intermittent scant hematochezia ^[8]

• Definition: chronic, intermittent passage of a small amount of blood from the rectum ^[8]
• Etiology
  • Hemorrhoids, anal fissures
  • Colorectal cancer, colon polyps
• Diagnostics
  • Perform DRE and flexible sigmoidoscopy for patients aged < 40 years without features of underlying malignancy or IBD. ^[8]
  • Colonoscopy is indicated for patients with any of the following:
    • Nondiagnostic sigmoidoscopy
    • Age > 50 years ^[8]
    • Unexplained red flags for colorectal cancer or IBD (e.g., weight loss, altered bowel habits, iron deficiency anemia)
    • Other risk factors for colorectal cancer (e.g., history of colonic polyps or family history of colorectal cancer)
• Management: Identify and treat the underlying cause, e.g., treatment of hemorrhoids or anal fissures.

Intermittent scant hematochezia is the most common form of LGIB. ^[8]

• Bleeding from the upper respiratory tract (e.g., nocturnal nosebleeds): Blood can be swallowed and vomited or appear in the stool as melena.
• Ingestions that can darken stool and resemble melena, e.g.:
  • Iron supplements
  • Bismuth preparations
• Certain foods or drinks with red coloring (e.g., licorice, soft drinks)

The differential diagnoses listed here are not exhaustive.

• Hemorrhagic shock
• Hepatic encephalopathy (in patients with liver cirrhosis)
• Aspiration pneumonia ^[29][30]

We list the most important complications. The selection is not exhaustive.

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