Gastrointestinal bleeding

Gastrointestinal (GI) bleeding can be caused by a number of conditions. It can manifest as overt GI bleeding with hematemesis, melena, or hematochezia, or as occult GI bleeding, with nonspecific symptoms related to iron deficiency anemia. GI bleeding can be classified as upper GI bleeding (UGIB) if the site of hemorrhage is proximal to the ligament of Treitz (e.g., esophageal variceal bleeding, bleeding peptic ulcer) or as lower GI bleeding (LGIB) if the site of hemorrhage is distal to the ligament of Treitz (e.g., diverticular bleeding, malignancy, small bowel bleeding). Overt UGIB typically manifests with hematemesis; hematochezia and melena may occur if the bleeding is brisk. Overt LGIB typically manifests with hematochezia; melena may occur if the bleeding is from the small bowel or proximal colon. The initial management of a patient with overt GI bleeding should focus on hemodynamic resuscitation and endoscopic identification of the source of hemorrhage, if feasible, or via angiography, followed by measures to control bleeding (endoscopically, surgically, or via angioembolization). Sigmoidoscopy is an appropriate initial investigation in young patients with scant hematochezia and no features of underlying malignancy or IBD. In all patients (i.e., with overt or occult GI bleeding), the underlying cause should be identified and treated.

• Upper gastrointestinal bleeding (UGIB)
  • ∼ 70–80% of GI hemorrhages ^[1]
  • The source of the bleeding is proximal to the ligament of Treitz (suspensory muscle of the duodenum).
• Lower gastrointestinal bleeding (LGIB)
  • ∼ 20–30% of all GI hemorrhages ^[2]
  • The source of the bleeding is distal to the ligament of Treitz, usually in the colon.
• Occult GI bleeding: bleeding in quantities too small to be macroscopically observable (requires chemical tests or microscopic examination to be detected)
• Overt GI bleeding: macroscopically observable bleeding with accompanying clinical symptoms (e.g., anemia, tachycardia)
• Obscure gastrointestinal bleeding: gastrointestinal bleeding that persists or recurs after an initial negative evaluation to find the source of bleeding.

Most common etiologies of GI bleeding ^[3]

See “Differential diagnosis of lower gastrointestinal bleeding in children.”

Bleeding from the upper respiratory tract (e.g., nocturnal nosebleeds) can be mistaken for GI bleeding because the blood can be swallowed and vomited or appear in the stool as melena. Careful examination and history taking is the key to differentiating respiratory sources of bleeding from GI ones.

• Anemia due to chronic blood loss
• Acute hemorrhage with significant blood loss
  • Signs of circulatory insufficiency or hypovolemic shock
    • Tachycardia, hypotension (dizziness, collapse, shock)
    • Altered mental status
  • Features of overt GI bleeding (see table below)

Both melena and hematochezia can be caused by either UGIB or LGIB.

Unexplained iron deficiency anemia (e.g., in men or postmenopausal women) should raise suspicion for GI bleeding.

The following recommendations are consistent with the 2021 American College of Gastroenterology (ACG) upper GI and ulcer bleeding guideline, the 2019 International Consensus Group (ICG) nonvariceal UGIB guidelines, the 2016 ACG LGIB guideline, and the 2014 American Society for Gastrointestinal Endoscopy (AGSE) LGIB guidelines. ^[5][6][7][8]

All patients ^{[5][6][7][8][9]}

• Ensure patient is NPO.
• Insert two large-bore peripheral IVs (for possible fluid resuscitation and blood transfusion) and obtain blood samples for laboratory studies (e.g., CBC, type and screen).
• Conduct a focused history and examination (including DRE).
• Risk stratify to guide further management.
• Consider the following prior to hemostatic procedures (see “Empiric pharmacotherapeutic interventions for GI bleeding” for details):
  • Pretreatment (e.g., IV PPI)
  • Anticoagulant reversal (e.g., for life-threatening bleeding)
  • Withholding antithrombotic agents

Upper endoscopy, colonoscopy, and transcatheter angiography are dual diagnostic/therapeutic procedures that allow rapid localization of the source of bleeding and hemostatic interventions.

Stable patients

• Restrictive transfusion strategy (transfuse pRBCs if Hb ≤ 7 g/dL). ^[6][7][8]
• Refer for endoscopy (e.g., EGD or colonoscopy) according to risk stratification and source of bleeding (see “Diagnostic approach to overt GI bleeding” and “Treatment”).

Unstable patients

• Follow an ABCDE approach.
• Consider intubation to protect the airway (e.g., in patients with altered mental state and/or severe ongoing hematemesis).
• Urgent volume resuscitation for hemodynamic instability
  • Insert a central line if peripheral venous access is not possible.
  • IV fluid resuscitation
  • Liberal transfusion strategy: for hemorrhagic shock or massive bleeding
    • pRBCs: should be given to unstable bleeding patients regardless of the initial hemoglobin level ^[6][7]
    • Platelets and/or FFP: for patients with coagulopathy or those requiring massive blood transfusions
  • Target normal vital signs prior to diagnostic testing if possible.
  • See also “Hypovolemic shock.”
• Determine optimal dual diagnostic/therapeutic intervention in consultation with specialists. .
  • See “Diagnostic approach to overt GI bleeding.”
  • Ensure prompt hemostatic control: i.e., endoscopy, angioembolization, or surgery (see “Treatment”).
• See “Management of esophageal variceal hemorrhage” for the management of suspected variceal bleeding.

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 crystalloid and blood product administration in these patients can increase the risk of rebleeding and death. ^[6][10]

Urgent consultations ^[11]

• All patients: gastroenterology
• Patients with ongoing bleeding and refractory hemodynamic instability or high-risk features of GI bleeding
  • Surgery
  • Interventional radiology

Consult surgery and interventional radiology early for patients with ongoing severe hemorrhage and high-risk features of GI bleeding (especially those too unstable to tolerate bowel preparation).

The measures described below should be initiated as soon as possible prior to procedures (e.g., endoscopy, angioembolization).

• Suspected bleeding peptic ulcer: Consider high-dose IV PPI infusion (e.g., omeprazole ). ^{[8][12][13][14]}
• Suspected esophageal variceal bleeding: See “Management of esophageal variceal hemorrhage” for more details.
  • Vasoactive therapy (e.g., octreotide , terlipressin) ^{[9][10][15][16]}
  • Empiric antibiotic therapy in patients with cirrhosis: Ceftriaxone is preferred. ^[10][15]
• Patients on antithrombotic agents: Consult specialists to decide when and how to withhold, adjust, or resume antithrombotics. ^[6][17][18]
  • Anticoagulants
    • Consider anticoagulant reversal for life-threatening bleeding.
    • Consider switching to unfractionated heparin in patients at high risk of rebleeding after hemostasis.
  • Antiplatelet agents
    • Review the indications for therapy with a specialist before withholding further doses.
    • Transfuse platelets only for thrombocytopenic patients or those with other indications for platelet transfusions (e.g., massive transfusion). ^[18]

Pretreatment other than anticoagulant reversal (if indicated) should not delay definitive diagnosis and hemostatic interventions.

Evidence does not support the routine use of tranexamic acid in patients with acute GI bleeding. ^[19]

Pre-endoscopy

All patients with GI bleeding should be risk-stratified to guide the diagnostic and therapeutic approach, timing of endoscopy, and patient disposition.

• Lower-risk clinical scenarios
  • Occult GI bleeding
  • Scant intermittent hematochezia due to benign anorectal disease (e.g., hemorrhoids, anal fissure)
• Higher-risk clinical scenarios
  • Overt GI bleeding with high-risk features
  • Esophageal variceal bleeding

• LGIB scoring systems: e.g., the Oakland score ^[20][21]
• UGIB scoring systems: e.g., the Glasgow-Blatchford score (GBS) ^[7][12]

Post-endoscopy ^[6][12][24]

• Colonoscopy: Inpatient treatment is recommended if there are features requiring intervention or associated with rebleeding.
• Upper endoscopy: The Forrest classification is commonly used to determine the need for hemostatic interventions during the procedure and can help guide disposition by predicting the risk of rebleeding.

Approach to low-risk GI bleeding

• Occult GI bleeding
  • Initial screening: fecal occult blood test (FOBT), CBC (± iron studies)
  • Nonurgent endoscopy if FOBT is positive
• Scant intermittent hematochezia
  • Initial screening for patients < 40 years old without features of underlying malignancy or IBD: DRE and sigmoidoscopy. ^[5]
  • Colonoscopy indicated for patients with:
    • Nondiagnostic sigmoidoscopy
    • Unexplained red flag symptoms for malignancy or IBD (e.g., weight loss, altered bowel habits, iron deficiency anemia)
    • Other risk factors for colorectal cancer

Approach to overt GI bleeding

Laboratory studies ^[9]

• Tests to assess the severity of GI bleeding (see “High-risk features of GI bleeding”)
  • CBC: Hb, Hct, platelet count
  • Coagulation panel
  • BMP: ↑ BUN/Cr ratio suggests a brisk UGIB ^[6]
• Blood type and crossmatching
• Liver chemistries: in suspected esophageal variceal hemorrhage

Anemia, low hematocrit, coagulopathy, and elevated BUN at presentation are signs of severe GI bleeding. ^[6]

An elevated BUN to creatinine ratio in a patient with hematochezia suggests a brisk UGIB. ^[6][29]

Nasogastric aspirate (NG aspirate) ^[6]

This test is not routinely recommended other than as an adjunct in patients with hematochezia with only moderate PTP of UGIB as the source. ^[5]

• Procedure: Instill 200–300 ml of warm isotonic saline via NG tube, then aspirate gastric contents for inspection. ^[30]
• Findings
  • Positive: Bright red blood or coffee-grounds; active UGIB confirmed ^[12][31]
  • Inconclusive: Nonbloody and nonbilious
  • Negative: Nonbloody and bilious ; active UGIB less likely

In patients with suspected UGIB, nasogastric tube aspiration is poorly sensitive as ∼ 15% of patients with active UGIB can have a false negative result. ^[12]

Endoscopy

These procedures allow for bleeding source identification, diagnostic biopsies (e.g., for gastric or colorectal cancer), and hemostatic interventions (e.g., epinephrine injection, vessel clipping). They should ideally be performed within 24 hours of admission.

• Upper endoscopy: a procedure during which a flexible fiber-optic instrument is passed through the mouth to visualize the inner layer of the upper GI tract up to the duodenal papilla
• Colonoscopy: a procedure during which a flexible fiber-optic instrument is passed through the anus to visualize the mucosa of the colon

EGD ^{[5][6][8][10][12]}

• Preparation
  • Bowel preparation medication is not routinely required.
  • Fasting (NPO) for > 2 hours (for clear liquids) and > 6–8 hours (for solids) is ideal. ^[32]
  • Consider the following to improve visualization if large amounts of blood, clots, or food suspected in the upper GI tract: ^[33]
    • NG tube lavage and suction
    • Prokinetic agents: e.g., erythromycin ^[8][24]
• Timing
  • Most patients: within 24 hours of presentation ^[8]
  • Suspected esophageal variceal bleeding: as soon as possible in unstable patients and within 12 hours in all other patients ^[10]
• Findings and further management (see “Treatment” for details)
  • Source of GI bleeding identified (positive EGD) : Attempt endoscopic hemostasis.
  • Source of GI bleeding not identified (negative or nondiagnostic EGD)
    • Hemodynamically stable patients with hematochezia or melena: Perform colonoscopy (if not performed as the first-line intervention); consider evaluation for small bowel bleeding. ^[26]
    • Hemodynamically unstable patients with ongoing bleeding: Consider angioembolization. ^[6]

Consider intubation prior to endoscopy if there is a high risk of aspiration.

Colonoscopy ^[5][6]

• Preparation
  • Rapid bowel preparation, e.g., polyethylene glycol solution : preferred for patients with acute LGIB requiring urgent colonoscopy and are stable enough to tolerate it.
  • Standard bowel preparation: for nonurgent or outpatient colonoscopy
• Timing ^[6][34]
  • High-risk clinical features and/or ongoing GI bleeding: within 24 hours of presentation (after rapid bowel prep)
  • All other inpatients: at the next available opportunity (after rapid bowel prep)
• Findings and further management (see “Treatment” for details)
  • Source of GI bleeding identified : Attempt endoscopic hemostasis.
  • Negative (nondiagnostic) colonoscopy
    • Hemodynamically stable patients: Evaluate for small bowel bleeding.
    • Hemodynamically unstable patients with ongoing bleeding: Consult surgery or angioembolization.

Lower endoscopy without bowel preparation (including sigmoidoscopy) is not recommended in the workup of acute LGIB. ^[6]

Angiography ^[28][29][35]

• Indications
  • Consider as the initial test in patients with suspected LGIB and hemodynamically instability refractory to resuscitation. ^[5][6]
  • Further workup of patients with ongoing bleeding and negative endoscopy ^[26][35]
• Options
  • Transcatheter angiography of the mesenteric vessels (visceral arteriography)
  • CT angiography (CTA): allows for rapid source localization to help target hemostatic interventions (e.g., angioembolization or surgery) ^[6]
• Findings: contrast extravasation at the site of active hemorrhage ^[29]
• Further management: angioembolization, surgical resection, or targeted endoscopic hemostasis (see “Treatment” section below) ^[29]

Optimize hydration before CTA or transcatheter angiography to mitigate the risk of contrast nephropathy (patients with severe GI bleeding are already at high risk due to hypovolemia).

Evaluation of small bowel bleeding ^[26][36]

Consider the following in addition to CT angiography:

• Advanced endoscopic evaluation: push enteroscopy, push-and-pull enteroscopy, video capsule endoscopy (VCE)
• Radiographic evaluation: CT enterography, tagged RBC scintigraphy, Meckel scan

VCE is preferred in hemodynamically stable patients with negative EGD and colonoscopy. Hemodynamically unstable patients with suspected small bowel bleeding should undergo angiography. ^[26]

Approach ^[5][6][7]

• Overt GI bleeding
  • Emergency resuscitation: See “Initial management of overt GI bleeding.”
  • Choice of source control modality depends on multiple factors (e.g., suspected hemorrhage source, hemodynamic status, available resources)
    • Endoscopy is indicated, feasible, and able to identify the source of bleeding: Attempt endoscopic hemostasis.
    • Endoscopy not recommended or unable to identify the source of bleeding: angioembolization or surgery
  • Identify and treat the underlying cause.
• Occult GI bleeding: Identify and treat the underlying cause; correct anemia (see “Treatment” in “Iron deficiency anemia”).
• Scanty intermittent hematochezia due to benign anorectal disease: See “Treatment” in “Hemorrhoids” and “Anal fissures.”

Endoscopic hemostasis ^[6][7][12]

• Indications: any high-risk endoscopic findings
  • Signs of active bleeding
  • Nonbleeding visible vessel
  • Adherent clot ^[7][12]
• Modalities ^[12]
  • Injection therapy; (e.g., with diluted epinephrine, normal saline)
  • Cauterization (e.g., heater probes, electrocauterization)
  • Mechanical therapy (e.g., band ligation, clips)
  • Polypectomy in the case of bleeding polyp (e.g., in the colon)

Interventional radiology (angiography) ^{[5][6][7][26][35]}

• Indications
  • Preferred therapy in patients with ongoing GI bleeding and hemodynamic instability refractory to resuscitation
  • An alternative to colonoscopy in patients with acute LGIB who cannot tolerate bowel preparation.
  • Consider in patients with rebleeding or ongoing bleeding despite endoscopic hemostasis. ^[28]
• Techniques
  • Angioembolization
  • Intraarterial vasopressin ^[11]

Surgery

• Indications
  • Consider if other therapeutic options have failed. ^[5]
  • Consider in hemodynamically unstable patients with ongoing bleeding.
• Procedure: exploratory laparotomy and surgical hemostasis

CTA for hemorrhage localization prior to surgery can help plan a more targeted intervention (e.g., bowel resection) and reduce perioperative risk (e.g., due to a missed source of bleeding). ^[6]

Treatment of the underlying cause

• Once hemostasis has been achieved, the underlying cause should be evaluated for and treated.
• For details, see “Treatment” in “Esophageal varices,” “Peptic ulcer disease,” “Diverticular disease,” “Colorectal cancer,” “IBD,” ”Dyspepsia.”

Determining patient disposition should be a multifactorial decision based on a combination of risk stratification, patient factors (e.g., functional status, support system), and available healthcare resources. ^{[5][6][9][12]}

Inpatient ^{[5][6][9][12][23]}

• Monitoring
  • Clinical: serial vital signs and monitoring for signs of hypovolemic shock
  • Laboratory: serial CBC, coagulation screen
  • Cardiovascular
    • Continuous cardiac monitoring for actively bleeding patients
    • Serial ECG for patients with CAD
• Hospital admission recommended for patients who do not fulfill the criteria for safe discharge, for example:
  • Glasgow-Blatchford score > 1
  • Any high-risk feature of GI bleeding
  • Endoscopic findings that require monitoring (e.g., Forrest classification more severe than IIc)
• ICU/CCU admission recommended if any of the following are present:
  • Evidence of ongoing hemorrhage or hypovolemic shock
  • Multiple high-risk features of GI bleeding
  • Esophageal variceal hemorrhage
  • High likelihood of rebleeding according to risk stratification scores (e.g., Glasgow-Blatchford score ≥ 7; Forrest I).

Outpatient ^{[5][6][8][9][12][23][37]}

• Discharge without a period of observation may be possible for patients with:
  • Occult GI bleeding without severe anemia
  • Scant hematochezia due to benign anorectal disease (e.g., anal fissures, hemorrhoids)
• Discharge after a period of observation can be considered if all the following parameters are met: The optimal duration of the observation period is unclear and practice varies (e.g., 6–24 hours).
  • Nonvariceal bleed
  • Hemodynamically stable patient, without evidence of ongoing hemorrhage
  • Clear source of bleeding that has been controlled.
  • Low-risk scores on risk stratification
    • No high-risk features of GI bleeding
    • Glasgow-Blatchford score ≤ 1
    • Forrest IIc–III
• Follow-up: Advise follow-up within 24 hours (earlier if symptoms recur) for further diagnostic evaluation and long-term management as needed.

All inpatients

• NPO
• ABCDE survey
• Consider continuous cardiac monitoring.
• IV fluid resuscitation as needed
• Transfuse pRBCs if Hb ≤ 7–8 g/dL (≤ 9 g/dL for unstable or high-risk patients).
• Obtain routine laboratory studies (e.g., CBC, coagulation panel, blood type and crossmatch, liver chemistries).
• Conduct pre-endoscopy risk stratification to determine diagnostic and therapeutic approach.
• Consider withholding antithrombotic agents as needed.
• Consider anticoagulant reversal.
• Consult specialist(s) for source control: e.g., gastroenterology, general surgery, interventional radiology.
• Evaluate and treat the underlying condition.
• Clinical monitoring, serial CBC and coagulation panel
• Admit to ward or critical care unit based on pre- and post-endoscopy risk stratification (See “High-risk features of GI bleeding”)

Suspected UGIB

• Consider intubation if risk of airway compromise.
• Start empiric pharmacological treatment if indicated.
  • PPI infusion for suspected PUD
  • Octreotide for suspected esophageal variceal bleeding
• Refer for EGD and endoscopic hemostasis.
• Patient unstable despite resuscitation: Consider angioembolization or surgery.
• See “Glasgow-Blatchford score” to help guide disposition.

Suspected LGIB

• Stable patients: Refer for colonoscopy
• Perform EGD first for unstable patients with hematochezia and any of the following:
  • High PTP of UGIB
  • Moderate PTP of UGIB with positive or inconclusive NG aspirate
• Consider colonoscopy first for unstable patients with hematochezia and all of the following:
  • Moderate PTP of UGIB and negative NG aspirate
  • Able to tolerate rapid bowel prep
• Consider angiography for patients with refractory hemodynamic instability
• Consider surgery if other options have failed

Differential diagnoses of upper GI bleeding

• Erosive or inflammatory
  • Peptic ulcer disease
  • Esophagitis
  • Erosive gastritis and/or duodenitis
  • Zollinger-Ellison syndrome
  • Cameron lesion
• Vascular
  • Varices (especially esophageal varices; also gastric, duodenal, or ectopic varices)
  • Gastric antral vascular ectasia
  • Dieulafoy lesion
  • Angiodysplasia
  • Angioma
  • Osler-Weber-Rendu disease
  • Watermelon stomach
  • Blue rubber bleb nevus syndrome
  • Telangiectasias
• Portal hypertensive gastropathy
• Tumors
  • Esophageal cancer
  • Gastric cancer
• Traumatic or iatrogenic
  • Mallory-Weiss tear
  • Hiatal hernia
  • Foreign-body ingestion
  • During surgery or endoscopy
  • Aortoenteric fistula
• Coagulopathies
• Hemobilia
• Hemosuccus pancreaticus

Differential diagnoses of lower GI bleeding

• Erosive or inflammatory
  • Diverticular disease
  • Ulcerative colitis
  • Crohn disease
  • Rectal ulcers
  • Stercoral ulcer
  • Celiac disease
  • Proctitis
• Vascular
  • Hemorrhoids
  • Ischemic colitis
  • Mesenteric ischemia
  • Arteriovenous malformation
  • Rectal varices
  • Angiodysplasia
  • Small bowel varices
• Tumors
  • Colorectal cancer
  • Anal cancer
  • Colonic polyps
  • Gardner syndrome
• Trauma or iatrogenic
  • Anorectal trauma
  • Lower abdominal trauma
  • During surgery or colonoscopy
  • Anastomotic bleeding
  • Aortoenteric fistula
• Coagulopathies
• Anal fissures
• Brisk UGIB
• Infectious colitis/enteritis
• Radiation-induced colitis
• Fecal impaction
• Meckel diverticulum

The differential diagnoses listed here are not exhaustive.

• Hypovolemic shock
• Hepatic encephalopathy (in patients with liver cirrhosis)
• Aspiration pneumonia ^[38][39]

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