Negative upper and lower endoscopy with ongoing bleeding
Laboratory Tests
Initial labs and interpretation
Baseline hemorrhage evaluation
Complete blood count for bleeding severity
Hb trend compared with baseline
Platelet count for procedural planning
Coagulation profile for reversal decisions
INR for warfarin effect
aPTT for heparin effect
Fibrinogen for massive bleeding physiology
Type and screen and crossmatch
If active bleeding, type and cross for multiple units
Electrolytes and renal function
Sodium mmol/L
Potassium mmol/L
Creatinine for contrast safety and dosing
Venous blood gas if shock
Lactate mmol/L
pH
Liver tests if chronic liver disease risk
ALT
AST
Bilirubin
Albumin
Targeted and conditional labs
Etiology-directed labs
Stool testing for suspected infectious colitis
C difficile toxin or PCR
Stool culture or multiplex PCR per local availability
Inflammatory markers for colitis pattern
CRP
Pregnancy test for reproductive potential
Serum beta-hCG
PITFALLS
Lab pitfalls
Early Hb may be falsely reassuring in acute hemorrhage
INR does not quantify DOAC activity
Lactate may be normal early in ischemic colitis
Diagnostic Tests
Scoring Systems
Risk stratification tools
Oakland score for safe discharge consideration
Age component
Sex component
Prior lower GI bleed admission
Digital rectal exam blood
Heart rate
Systolic blood pressure
Hemoglobin g/L
Discharge consideration at low score with no ongoing bleeding and stable vitals
NOBLADS score for severe lower GI bleeding risk
NSAID use
No diarrhea
No abdominal tenderness
Systolic blood pressure low
Antiplatelet use
Albumin low
Charlson comorbidity index high
Syncope
MRI
Limited role in acute lower GI hemorrhage
Indications
Suspected perianal Crohn disease complications when stable
Pelvic source evaluation when stable
Constraints
Not suitable for hemodynamically unstable bleeding
Limited acute bleeding localization performance
CT
CT-based localization and complications
CT angiography abdomen and pelvis
Indications
Ongoing brisk hematochezia
Hemodynamic instability
Inability to tolerate bowel prep
Protocol considerations
Noncontrast phase if concern for high attenuation stool
Arterial phase for extravasation
Portal venous phase for delayed bleeding
Interpretation pearls
Active extravasation into bowel lumen
Diverticulosis distribution
Colitis pattern
Mesenteric ischemia findings
Downstream actions
If positive extravasation, interventional radiology embolization pathway
If negative with ongoing bleeding, colonoscopy after prep or nuclear scan based on local resources
CT abdomen and pelvis with IV contrast
Indications
Suspected ischemic colitis or perforation
Suspected malignancy complications
Ultrasound (or US)
Point-of-care ultrasound integration
Shock evaluation
Cardiac function assessment
Pericardial effusion
IVC size and collapsibility
Volume status adjunct
Lung B-lines for fluid overload risk
Abdominal adjunct
Free fluid assessment
Aortic aneurysm screen in older patients with collapse
Disposition
Level of care decisions
Admission criteria
Hemodynamic instability
Ongoing bleeding in ED
Need for transfusion
Significant comorbidities
Anticoagulant reversal required
High-risk scores
ICU criteria
MTP activation
Vasopressor requirement
Persistent lactate elevation
Active bleeding with repeated transfusion
Transfer criteria
No endoscopy capability for urgent colonoscopy
No interventional radiology for embolization
No surgical backup for refractory bleeding
Discharge criteria
Low-risk discharge pathway
Hemodynamic stability without orthostasis
No further bleeding during observation
Hb stable on serial checks
Reliable follow-up within 7-14 days
Clear return precautions
Consider low Oakland score support
Treatment
General measures and supportive care
Immediate supportive care
NPO while active bleeding or pending procedures
IV crystalloid for initial shock bridge
Early PRBC transfusion for hemorrhagic shock
Avoid routine prophylactic antibiotics unless specific indication
Avoid routine tranexamic acid for GI bleeding due to thromboembolic risk concern
Anticoagulant and antiplatelet reversal
Warfarin-associated bleeding
Reversal bundle
Four-factor PCC IV per weight and INR protocol
If INR elevated with life-threatening bleed, immediate PCC
Repeat INR after PCC per protocol
Vitamin K IV 10 mg
Slow infusion to reduce reaction risk
Dabigatran-associated bleeding
Specific reversal
Idarucizumab IV 5 g
Two 2.5 g doses
Consider repeat dosing if rebound and ongoing bleeding
Factor Xa inhibitor-associated bleeding
Reversal options
Andexanet alfa IV per protocol if available
Dose based on agent and last dose timing
Thrombosis monitoring plan
Four-factor PCC IV 50 units/kg if andexanet unavailable
Max dose per protocol
Heparin-associated bleeding
Protamine sulfate IV
Dose based on heparin exposure timing
Infusion rate limitation to reduce hypotension
Antiplatelet-associated bleeding
Hold strategy
Hold P2Y12 inhibitor during active life-threatening bleed when feasible
Continue aspirin for secondary prevention if possible
Platelet transfusion
Consider if life-threatening bleeding with planned urgent procedure
Avoid routine transfusion for aspirin alone without procedural need
Endoscopic therapy pathway
Colonoscopy-based management
Timing strategy
If ongoing bleeding but stable, early colonoscopy after rapid bowel prep
If bleeding stopped, inpatient or expedited outpatient colonoscopy based on risk
Bowel preparation
Polyethylene glycol electrolyte solution
High-volume split dosing to clear effluent
Nasogastric tube administration if unable to drink
Endoscopic hemostasis options
Through-the-scope clips
Diverticular stigmata
Visible vessel
Thermal coagulation
Angiodysplasia
Epinephrine injection as adjunct
Not as sole definitive therapy
Interventional radiology and surgical therapy
Angiography and embolization
Indications
Positive CTA extravasation
Persistent bleeding with hemodynamic compromise
Embolization principles
Superselective embolization to reduce ischemia risk
Post-embolization monitoring for ischemic colitis
Surgical management
Indications
Refractory massive bleeding despite endoscopy and IR
Suspected bowel ischemia with peritonitis
Aortoenteric fistula concern
Localization importance
Segmental colectomy if localized source
Subtotal colectomy if uncontrolled and nonlocalized
Special Populations
Pregnancy
Pregnancy-specific considerations
Common etiologies
Hemorrhoids
Anal fissure
Inflammatory bowel disease flare
Imaging considerations
Avoid ionizing radiation when possible
If life-threatening bleeding, CTA acceptable with shared decision-making
Medication considerations
Avoid teratogenic drugs
Anticoagulant reversal coordination with obstetrics
Geriatric
Older adult considerations
High-prevalence etiologies
Diverticular hemorrhage
Angiodysplasia
Colorectal cancer
Comorbidity risk
Lower physiologic reserve
Higher transfusion risk for volume overload
Medication burden
Anticoagulant and antiplatelet polypharmacy
Renal dysfunction affecting DOAC clearance
Pediatrics
Pediatric considerations
Age-specific etiologies
Anal fissure in infants
Milk protein allergy in infants
Intussusception with currant jelly stool
Meckel diverticulum with painless bleeding
Juvenile polyp with intermittent bleeding
Resuscitation differences
Weight-based blood products
Early pediatric consultation
Diagnostic priorities
Meckel scan for suspected Meckel diverticulum
Ultrasound for intussusception
Background
Epidemiology
Epidemiology basics
Frequency
Lower GI bleeding common cause of hospitalization in adults
Incidence increases with age
Common adult etiologies
Diverticular bleeding
Angiodysplasia
Ischemic colitis
Outcomes
Many episodes self-limited
Rebleeding risk significant in diverticular and angiodysplasia sources
Pathophysiology
Mechanisms by etiology
Diverticular hemorrhage
Ru
SymptomDx is an educational tool for medical professionals. It does not replace clinical judgment. Verify all clinical data and drug dosages with authoritative sources.