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.
See also “Esophageal variceal hemorrhage”.
- Upper gastrointestinal bleeding (UGIB)
- Lower gastrointestinal bleeding (LGIB)
- 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 
|Overview of the most common etiologies of GI bleeding|
|Erosive or inflammatory|| || |
|Tumors|| || |
|Traumatic or iatrogenic|| |
|Other causes|| |
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.
- Definition: a common degenerative disorder of GI vessels (mostly venous) that can cause GI bleeding
- Epidemiology: predominantly seen in individuals > 60 years of age 
- Etiology: associated with , Heyde syndrome), and (e.g., (ESRD)
- Pathophysiology: poorly understood (a potential influencing factor is low-grade venous obstruction of submucosal veins)
- Clinical features
- Laboratory studies
Endoscopy: the preferred method for establishing diagnosis
- Lesions are usually multiple tortuous dilated vessels, most commonly located in the right-sided colon 
- Angiodysplasias have a characteristic appearance: 5–10 mm in size, flat, cherry-red color with a fern-like pattern that radiates from a central vessel.
- Vessels are usually ectatic, thin-walled, and are either composed of endothelium alone or contain small amounts of smooth muscle.
- In most cases, vascular malformations affect veins, but arteriovenous and arterial changes may also occur.
- Gold standard
- Indication: recurrent bleeding with inconclusive endoscopy
- Intraoperative enteroscopy is used in cases where bleeding could not be identified either endoscopically or radiographically.
- Differential diagnosis: diverticulosis, colorectal cancer
- Incidentally detected angiodysplasia should not be treated.
- Endoscopically bleeding angiodysplasia or nonbleeding angiodysplasia with iron deficiency anemia or evidence of GI bleeding:
- First-line: endoscopic treatment, e.g., using cautery, argon plasma coagulation, electrocoagulation, clipping, and injection sclerotherapy
- Angiography; (e.g., using embolization or vasopressin infusion): if endoscopy has failed or is not an option
- Surgery (e.g., surgical resection): in the case of severe active bleeding (e.g., requiring multiple blood transfusions)
- Antiangiogenic medication (e.g., bevacizumab, thalidomide): if the lesion is inaccessable to endoscopy or in the case of multiple or recurrent bleedings
- Hormone therapy (e.g., estrogen with or without progesterone): used to control bleeding in patients with conditions such as ESRD or von Willebrand disease
- Complications: anemia and/or life-threatening bleeding
- Anemia due to chronic blood loss
- Acute hemorrhage with significant blood loss
|Features of overt GI bleeding|
The following recommendations are consistent with the 2019 International Consensus Group (ICG) nonvariceal UGIB guidelines, the 2016 American College of Gastroenterology (ACG) LGIB guideline, the 2014 American Society for Gastrointestinal Endoscopy (AGSE) LGIB guidelines. 
All patients 
- 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, ).
- Conduct a focused history and examination (including DRE).
- Risk stratify to guide further management.
- Prior to hemostatic procedures: (see “Empiric pharmacotherapeutic interventions for GI bleeding” for details)
- Restrictive transfusion strategy (transfuse pRBCs if Hb ≤ 7–8 g/dL). 
- Refer for endoscopy (e.g., EGD or colonoscopy) according to risk stratification and source of bleeding (see “ ” and “Treatment”).
- 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
- Target normal vital signs prior to diagnostic testing if possible.
- See also “Hypovolemia shock.”
- Determine optimal dual diagnostic/therapeutic intervention in consultation with specialists. .
- See “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. 
Urgent consultations 
- All patients: gastroenterology
- Patients with ongoing bleeding and refractory hemodynamic instability or
- Interventional radiology
These measures should be initiated as soon as possible prior to procedures (e.g., endoscopy, angioembolization)
- Suspected bleeding peptic ulcer: high-dose IV PPI infusion (e.g., omeprazole ) 
Patients on antithrombotic agents: Consult specialists to decide when and how to withhold, adjust, or resume antithrombotics. 
- INR > 2.5 at admission: Administer to achieve INR ≤ 2.5 before endoscopy.
- INR ≤ 2.5: Do not delay endoscopic hemostasis for anticoagulant reversal.
- If further doses of anticoagulants cannot be stopped, consider switching to unfractionated heparin in patients at high risk of rebleeding after hemostasis.
- Transfuse platelets in patients with severe or life-threatening hemorrhage.
- Review the indications for therapy with a specialist before withholding further doses.
Evidence does not support the routine use of tranexamic acid in patients with acute GI bleeding. 
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
- Higher-risk clinical scenarios
|High-risk features of GI bleeding |
|Features at presentation|
|Interpretation: > 1 feature is associated with a risk of severe or recurrent bleeding|
- LGIB scoring systems: e.g., the Oakland score 
- UGIB scoring systems: e.g., the Glasgow-Blatchford score (GBS) 
|Glasgow Blatchford score |
|Laboratory features||BUN||< 18.2 mg/dL||0|
|18.2 mg/dL–22.3 mg/dL||2|
|22.4 mg/dL–27.9 mg/dL||3|
|28 mg/dL–69.9 mg/dL||4|
|≥ 70 mg/dL||6|
|Hemoglobin||♂: > 13 g/dL||♀: > 12 g/dL||0|
|♂: 12–13 g/dL||♀: 10–12 g/dL||1|
|♂: 10–12 g/dL||♀: N/A||3|
|♂: < 10 g/dL||♀: < 10 g/dL||6|
|Clinical features||Systolic blood pressure||> 110 mm Hg||0|
|100–109 mm Hg||1|
|90–99 mm Hg||2|
|< 90 mm Hg||3|
|Additional criteria|| |
Heart rate ≥ 100/min
|Melena at presentation||1|
|Syncope at presentation||2|
- 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.
|Forrest classification of bleeding peptic ulcers |
|Stage||Description||Risk of recurring hemorrhage|
|Ia||Spurting arterial hemorrhage||∼ 90%|
|Ib||Actively oozing hemorrhage||∼ 50%|
Evidence of a recent hemorrhage
|IIa||Nonbleeding ulcer with a visible vessel||∼ 50%|
|IIb||Ulcer with an adherent clot||∼ 30%|
|IIc||Flat ulcer with a dark base (covered with hematin)||∼ 10%|
|III||Flat ulcer base (no active hemorrhage)||< 5%|
Monitoring and disposition
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. 
- Hospital admission recommended for patients who do not fulfill the criteria for safe discharge, for example:
- ICU/CCU admission recommended if any of the following are present:
- Discharge without a period of observation may be possible for patients with:
- 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).
- Follow-up: Advise follow-up within 24 hours (earlier if symptoms recur) for further diagnostic evaluation and long-term management as needed.
Approach to low-risk GI bleeding
- Occult GI bleeding
- Scant intermittent hematochezia
- Initial screening for patients < 40 years old without features of underlying malignancy or IBD: DRE and sigmoidoscopy. 
- Colonoscopy indicated for patients with:
Approach to overt GI bleeding
|Diagnostic approach for overt GI bleeding |
|Suspected UGIB ||Suspected LGIB |
|Supportive features |
|Testing strategy for hemodynamically stable patients|
|Testing strategy for hemodynamically unstable patient|| || |
Laboratory studies 
- Tests to assess the severity of GI bleeding (see “High-risk features of GI bleeding”)
- Blood type and crossmatching
- Liver chemistries: in suspected
Nasogastric aspirate (NG aspirate) 
- Procedure: Instill 200–300 ml of warm isotonic saline via NG tube, then aspirate gastric contents for inspection. 
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
- Bowel preparation medication is not routinely required.
- Fasting (NPO) for > 2 hours (for clear liquids) and > 6–8 hours (for solids) is ideal. 
- Consider the following to improve visualization if large amounts of blood, clots, or food suspected in the upper GI tract: 
- Within 13–24 hours of admission for most patients, especially those with 
- Within 12 hours of admission if for suspected esophageal variceal bleeding 
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)
- Timing 
- Findings and further management (see “Treatment” for details)
- Consider as the initial test in patients with suspected LGIB and hemodynamically instability refractory to resuscitation. 
- Further workup of patients with ongoing bleeding and negative endoscopy 
- Findings: contrast extravasation at the site of active hemorrhage 
- Further management: angioembolization, surgical resection, or targeted endoscopic hemostasis (see “Treatment” section below) 
Evaluation of small bowel bleeding 
Consider the following in addition to CT angiography:
- Advanced endoscopic evaluation: VCE) , , (
- Radiographic evaluation: , ,
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)
- 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 “ ” and “Anal fissures.”
Endoscopic hemostasis 
Indications: any high-risk endoscopic findings
- Signs of active bleeding
- Nonbleeding visible vessel
- Adherent clot 
- Modalities 
Interventional radiology (angiography) 
- 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. 
- Consider if other therapeutic options have failed. 
- Consider in hemodynamically unstable patients with ongoing bleeding.
- Procedure: exploratory laparotomy and surgical hemostasis
Treatment of the underlying cause
- Once hemostasis has been achieved, the underlying cause should be evaluated for and treated.
- For details, see “Treatment” in “ ,” “ ,” “ ,” “ ,” “ .”
Differential diagnoses of upper GI bleeding
- Erosive or inflammatory
- Portal hypertensive gastropathy
- Traumatic or iatrogenic
- Hemosuccus pancreaticus
Differential diagnoses of lower GI bleeding
- Erosive or inflammatory
- Trauma or iatrogenic
- Anal fissures
- Brisk UGIB
- Infectious colitis/enteritis
- Radiation-induced colitis
- Fecal impaction
- Meckel diverticulum
The differential diagnoses listed here are not exhaustive.
- liver cirrhosis) (in patients with
We list the most important complications. The selection is not exhaustive.
Acute management checklist
- 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.
- Administer anticoagulant reversal if INR > 2.5.
- 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”)
- Consider intubation if risk of airway compromise.
- Start empiric pharmacological treatment if indicated.
- Refer for EGD and endoscopic hemostasis.
- Patient unstable despite resuscitation: Consider angioembolization or surgery.
- See “Glasgow-Blatchford score” to help guide disposition.
- Stable patients: Refer for colonoscopy
- Perform EGD first for unstable patients with hematochezia and any of the following:
- Consider colonoscopy first for unstable patients with hematochezia and all of the following:
- Consider angiography for patients with refractory hemodynamic instability
- Consider surgery if other options have failed