01Approach to the Critical Patient/attcp60

Immediate priorities

›Hemorrhagic shock recognition

›Hypotension SBP <90 mmHg

›Two large-bore IVs (18G or larger) immediately

›Crystalloid bolus 1–2 L while awaiting blood

›Tachycardia HR >100 with shock index >=1 (HR/SBP)

›Activate massive transfusion protocol if ongoing hemodynamic compromise

›Type and crossmatch 4 units pRBCs

›Altered mental status from hemorrhagic shock

›Airway protection if GCS <8

›Immediate escalation to resuscitation bay

›Resuscitation targets

›SBP >=90 mmHg after initial fluid resuscitation

›MAP >=65 mmHg

›Urine output >=0.5 mL/kg/hr

›Transfuse pRBCs if Hb <70 g/L (restrictive threshold)

›Hb target <80 g/L in active myocardial ischemia

›Reassess hemoglobin after resuscitation as early values may be falsely normal

›Platelet target >50 x10^9/L before endoscopy

›>30 x10^9/L in severe ongoing hemorrhage

›Hold antithrombotic agents

›Warfarin: hold and consider 4-factor PCC for INR substantially supratherapeutic with life-threatening bleeding

›Preferred over FFP for reversal

›Avoid routine reversal in therapeutic-range anticoagulation

›DOACs: hold; idarucizumab for life-threatening dabigatran-associated hemorrhage

›Andexanet alfa has been withdrawn from the US market

›Aspirin for secondary cardiovascular prevention: continue without interruption

›Aspirin for primary prevention only: discontinue after diverticular bleed

02History/hx85

Presentation pattern

›Cardinal symptom: painless hematochezia

›Bright red or maroon blood per rectum, typically large-volume

›Abrupt onset without prodrome

›Cathartic effect may cause multiple bloody bowel movements

›Mild cramping or bloating from intraluminal blood

›Significant abdominal pain should prompt consideration of alternative diagnoses

›Pain with bloody diarrhea suggests ischemic colitis or infectious colitis

›Duration and volume assessment

›Number of bloody bowel movements

›Presence of clots indicating arterial bleed

›Symptom timeline

›Onset: sudden, often without warning

›Ask whether bleeding has slowed or stopped

›Syncope or presyncope during episode

›Prior episodes of lower GI bleeding

›Prior diverticular bleed (strongest predictor of recurrence)

›Known diverticulosis on colonoscopy

Alarm features

›Hemodynamic compromise signs

›Lightheadedness or dizziness

›Syncope or presyncope

›Inability to stand without dizziness

›Tachycardia or palpitations

›Chest pain with significant anemia

›Dyspnea from hemorrhage-related demand ischemia

›Decreased urine output from hypovolemia

›Confusion or altered mental status

›Cool or clammy extremities

›Features suggesting alternative diagnosis

›Melena or hematemesis

›Raises concern for upper GI source (10–15% of hematochezia cases)

›Brisk upper GI hemorrhage can produce bright red blood per rectum

›Fever, diarrhea, or abdominal pain

›Ischemic colitis, infectious colitis, or inflammatory bowel disease

›Peritoneal signs suggest perforation

›Weight loss, change in bowel habits

›Colorectal neoplasia concern

›Occult or overt bleeding from malignancy

Medication history

›Antithrombotic agents

›Aspirin and NSAIDs: pooled relative risk of LGIB approximately 1.8

›NSAIDs HR 8.61 for diverticular bleed in cohort studies

›Aspirin HR 2.75 for diverticular bleed

›P2Y12 inhibitors (clopidogrel): independent risk factor

›Thienopyridine use associated with increased long-term rebleeding (SHR 1.24–1.32)

›Combination antithrombotic/antiplatelet therapy carries highest risk

›Anticoagulants (warfarin, DOACs)

›Combination anticoagulant plus antiplatelet incidence 70 per 1,000 person-years

›INR supratherapeutic status

›Other medications

›Corticosteroids: may contribute to diverticular disease risk

›Opioids: may contribute to diverticular disease risk

›Recent colonoscopy or polypectomy

›Postpolypectomy bleed mimic

›Timing of procedure

Risk factors

›Diverticular disease risk factors

›Age >50 years

›Prevalence of diverticulosis increases with age

›Age >70 predictive of new-onset diverticular bleeding

›Known diverticulosis

›Cumulative hemorrhage risk 0.21% at 1 year, 2.2% at 5 years, 9.5% at 10 years

›Right and bilateral diverticulosis has higher bleeding risk than left-sided alone

›Prior diverticular bleed

›Strongest predictor of recurrence

›Recurrence rate up to 25% at 5 years

›Comorbid conditions

›Hypertension and atherosclerotic cardiovascular disease

›Associated with late rebleeding

›Chronic kidney disease: additional late rebleeding risk

›Chronic liver disease

›Coagulopathy risk

›Portal hypertension with possible anorectal varices

›Prior abdominal or pelvic surgery or radiation

›Radiation proctopathy as alternative bleeding source

›Aortic aneurysm repair raises concern for aortoenteric fistula

Review of systems

›GI symptoms

›Hematochezia: volume, frequency, color

›Melena suggesting upper GI or proximal colonic source

›Hematemesis ruling in upper GI source

›Abdominal pain, diarrhea, constipation

›Weight loss or change in bowel habits suggesting malignancy

›Nausea or vomiting

›Systemic symptoms

›Fever suggesting infectious or inflammatory etiology

›Fatigue from chronic or subacute blood loss

›Decreased urine output from hypovolemia

›Chest pain or palpitations from demand ischemia or arrhythmia

03Physical Exam/exam41

Vital signs

›Hemodynamic assessment

›Blood pressure

›SBP <90 mmHg indicates hemodynamic instability

›Orthostatic changes: drop in SBP >20 mmHg or HR rise >20 on standing

›Heart rate

›Tachycardia HR >100 as hemorrhage marker

›Shock index HR/SBP >=1 indicates hemodynamic instability

›Respiratory rate and oxygen saturation

›Tachypnea from hemorrhage-induced demand

›SpO2 reduction from anemia and poor perfusion

›Temperature

›Fever suggests infectious or inflammatory etiology

›Ischemic colitis, infectious colitis

›Absence of fever does not exclude ischemia

Abdominal and rectal exam

›Abdominal examination

›Typically benign in isolated diverticular bleeding

›Tenderness or peritoneal signs suggest alternative diagnosis

›Distension raising concern for bowel obstruction or perforation

›Liver and spleen assessment

›Hepatomegaly or splenomegaly suggesting portal hypertension

›Ascites from liver disease

›Digital rectal exam

›Stool color: bright red or maroon typical of diverticular bleed

›Melena suggests upper GI or proximal source

›Blood on DRE is a component of Oakland score

›Anorectal pathology

04Differential Diagnosis/ddx47

Life-threatening diagnoses

›Massive upper GI bleed presenting as hematochezia

›ICD-10 K92.2 gastrointestinal hemorrhage unspecified

›10–15% of patients with hematochezia have upper GI source

›Brisk peptic ulcer, Dieulafoy lesion, or variceal bleed

›Hematemesis or melena absent does not exclude upper GI source

›Perform upper endoscopy first if hemodynamically unstable

›Mesenteric ischemia

›ICD-10 K55.0 acute vascular disorders of intestine

›Severe abdominal pain disproportionate to findings

›Risk factors: atrial fibrillation, hypercoagulable state, shock

›Lactic acidosis from bowel infarction

›CT angiography for mesenteric vessels

›Aortoenteric fistula

›Prior aortic aneurysm repair (endovascular or open)

›Herald bleed may precede massive hemorrhage

›CT aorta with contrast urgent investigation

Common causes of lower GI bleed

›Ischemic colitis

›ICD-10 K55.1

›Abdominal pain is distinguishing feature from diverticular bleed

›Typically left-sided distribution (watershed areas: splenic flexure, sigmoid)

›Risk factors: cardiovascular disease, hypotension, dehydration

›Bloody diarrhea with cramping

›Angiodysplasia and arteriovenous malformations

›ICD-10 K55.20 angiodysplasia of colon without hemorrhage

›Painless bleeding, often right-sided

›More common in elderly and those with CKD or aortic stenosis

05Laboratory Tests/lt41

Core hemorrhage labs

›Complete blood count

›Hemoglobin/hematocrit

›May be falsely normal early in acute bleed before equilibration

›Recheck every 4–6 hours during active bleeding

›Platelet count

›Target >50 x10^9/L before endoscopy

›>30 x10^9/L for severe ongoing hemorrhage

›Leukocytosis suggesting infectious or inflammatory etiology

›Normal WBC does not exclude ischemic colitis

›Coagulation studies

›PT/INR: supratherapeutic INR in warfarin-treated patients

›PTT: prolonged in heparin therapy or factor deficiency

›Thromboelastography or ROTEM if massive hemorrhage protocol activated

›Type and screen/crossmatch

›Essential for potential transfusion

›Crossmatch 4 units pRBCs in hemodynamically unstable patient

Metabolic and organ function labs

›Basic metabolic panel

›BUN/creatinine ratio

›BUN/Cr >30 (or >20 in SI units) may suggest upper GI source

›Elevated creatinine impacts antibiotic and contrast decisions

›Electrolytes

›Hypokalemia from gastrointestinal losses

›Metabolic acidosis from hypoperfusion

›Liver function tests

›Transaminases, bilirubin, albumin if liver disease suspected

›Coagulopathy risk stratification

06Diagnostic Tests/dt77

Scoring Systems

›Oakland Score (best validated tool for LGIB disposition)

›Score components

›Age: <40 years (0), 40–69 years (1), >=70 years (2)

›Sex: female (0), male (1)

›Previous LGIB admission: no (0), yes (1)

›DRE findings: no blood (0), blood present (1)

›Heart rate: <70 (0), 70–89 (1), 90–109 (2), >=110 (3)

›Score interpretation

›Score <=8: 95% probability of safe discharge (sensitivity 98%)

›ACG recommends use to supplement (not replace) clinical judgment

›Score >8: hospital admission indicated

›NOBLADS Score (severity prediction)

›Predicts severe LGIB (AUROC 0.77)

›Components: NSAIDs, no diarrhea, no abdominal tenderness, blood pressure low, low albumin, antiplatelet drugs, syncope

›Higher score predicts more severe bleeding episode

›Strate Score

›Predicts in-hospital recurrent bleeding

›Heart rate >100, SBP <115 mmHg, syncope, non-tender abdomen, aspirin use, bleeding from 2 or more sites

›Score >=3 predicts high risk of recurrence

›SHA2PE Score

›Identifies low-risk patients for LGIB

›Validated for early discharge decision support

›Complements Oakland score in risk stratification

MRI

›MRI role in lower GI bleed

›Limited utility in acute hemorrhage

›Availability and time constraints in acute setting

›Motion artifact from bowel peristalsis reduces image quality

›Problem-solving indications

›Suspected occult colorectal or small bowel malignancy

›Complex pelvic pathology after acute bleeding episode resolved

›MRI enterography for obscure GI bleeding

›Identifies small bowel lesions missed by colonoscopy and CTA

›Considered after negative bidirectional endoscopy and CTA

›Contraindications in acute setting

›Hemodynamically unstable patient

›Non-MRI-compatible implants

CT

›CT angiography (CTA)

›Imaging modality of choice for hemodynamically significant or severe bleeding

›Sensitivity approximately 90% for active extravasation

›Guides transcatheter arterial embolization if extravasation identified

›Nearly 80% of patients with negative CTA will have no rebleeding

›Negative CTA does not require further emergent evaluation in most cases

›ACR Appropriateness Criteria support CTA as first-line imaging for severe LGIB

›CTA protocol

›Non-contrast, arterial phase, and portal venous phase triphasic protocol

›Contrast extravasation on arterial phase indicates active hemorrhage

›Fluid collection adjacent to diverticulum may indicate site of recent bleed

›Limitations

›Requires active bleeding at rate >=0.3–0.5 mL/min for detection

›Radiation exposure consideration in younger patients

›Contrast nephropathy risk with pre-existing renal impairment

Ultrasound

›FAST exam and abdominal ultrasound

›Intraperitoneal free fluid assessment

›Relevant if perforation or mesenteric pathology suspected

›Limited utility for direct diverticular visualization

›Hepatic parenchyma and spleen assessment

›Portal hypertension evidence

›Ascites from liver disease

›POCUS for hemodynamic assessment

›Inferior vena cava collapsibility for fluid responsiveness

›IVC collapsibility >50% suggests volume responsiveness

›Limitations in spontaneously breathing patient

›Left ventricular function assessment

›Gross LV function estimate to guide resuscitation

›Pericardial effusion screen

›Limitations

›Operator-dependent technique

›Bowel gas limits diverticular visualization

›ACEP Level B recommendation for IVC assessment as adjunct to fluid responsiveness

›Tagged RBC scan (Tc-99m scintigraphy)

›Role in intermittent or obscure lower GI bleeding

›Can detect bleeding at lower flow rates than CTA (0.1–0.4 mL/min)

›Not routinely recommended as first-line imaging

›Limitations

›Cannot guide direct therapeutic intervention

›Limited anatomic precision for surgical localization

›Time to positive scan variable; may miss intermittent bleeds

07Disposition/dispo44

Discharge criteria

›Low-risk outpatient management criteria

›Oakland score <=8

›Self-limited bleeding with cessation of hematochezia

›Hemodynamically stable: SBP >=90 mmHg, HR <100

›Hemoglobin stable and above transfusion threshold

›No ongoing transfusion requirement

›Ability to maintain oral hydration

›Adequate follow-up plan

›Outpatient GI follow-up with colonoscopy within 14 days

›PCP follow-up within 1–2 weeks for repeat CBC and medication review

›Safe discharge conditions

›Recent colonoscopy within 12 months showing diverticulosis without other concerning findings

›Low-risk scoring by Oakland score with near-zero hospital admission probability

›Reliable patient with return precaution understanding

›No anticoagulant use with supratherapeutic INR

›No active cardiac ischemia or other comorbid decompensation

Admission criteria

›Inpatient level-of-care indications

›Oakland score >8

›Ongoing hematochezia at time of assessment

›Significant anemia requiring transfusion

›Hemodynamic instability

›SBP <90 mmHg despite initial resuscitation

›Persistent tachycardia HR >100 after fluid challenge

›High-risk patient features

›Anticoagulant use with supratherapeutic INR

›Elderly patients with suspected diverticular bleeding generally managed inpatient

08Treatment/t89

Initial resuscitation

›Vascular access and volume

›Two large-bore peripheral IVs (18G or larger)

›Intraosseous access if peripheral access fails in hemodynamic collapse

›Central venous access if massive transfusion protocol activated

›Crystalloid resuscitation

›1–2 L normal saline or lactated Ringer's bolus for hemodynamic instability

›Avoid over-resuscitation once BP responds; blood products preferred over crystalloid

›Blood product transfusion

›pRBCs: transfuse if Hb <70 g/L (restrictive threshold)

›Hb target <80 g/L in active myocardial ischemia or significant cardiac disease

›Monitoring

›Continuous cardiac monitoring

›Pulse oximetry and blood pressure every 15–30 minutes during active bleeding

›Foley catheter for urine output monitoring in hemodynamically unstable patient

›Serial hemoglobin every 4–6 hours

›Serial vital signs to assess resuscitation response

›Repeat lactate in 2–4 hours if initially elevated

Anticoagulation and antiplatelet management

›Warfarin reversal

›Hold warfarin on admission

›4-factor PCC (Kcentra) for life-threatening bleeding with INR substantially supratherapeutic

›Dose: 25 units/kg IV for INR 2–4; 35 units/kg for INR 4–6; 50 units/kg for INR >6

›FFP as alternative if PCC unavailable

›10–15 mL/kg IV; less predictable and requires larger volume

›Vitamin K 10 mg IV for sustained reversal

›DOAC management

›Hold all DOACs on admission

›Idarucizumab (Praxbind) 5 g IV (2 x 2.5 g vials) for life-threatening dabigatran-associated hemorrhage

›Andexanet alfa withdrawn from US market; not available

›Activated charcoal if DOAC ingested within 2 hours

›50 g PO if patient can protect airway

›Antiplatelet management

›Aspirin for secondary cardiovascular prevention: continue without interruption

›Risk of cardiovascular events outweighs diverticular rebleed risk in this context

›ACEP Level B recommendation for aspirin continuation in secondary prevention

›Aspirin for primary prevention: discontinue after diverticular bleed

›Benefit-risk balance favors discontinuation after first diverticular bleed

›P2Y12 inhibitors (clopidogrel, ticagrelor, prasugrel)

›May be temporarily held during acute bleed

›Resume within 1–7 days after cessation of bleeding

›Coordinate with cardiology if recent coronary stent (timing critical)

›Tranexamic acid: avoid in LGIB

›Associated with increased thromboembolism and seizure without outcome benefit

›Not recommended by ACG guidelines for LGIB

Endoscopic treatment

›Colonoscopy preparation and timing

›Bowel preparation with polyethylene glycol (PEG) solution

›4–6 L PEG over 3–4 hours before colonoscopy

›Metoclopramide 10 mg IV to accelerate gastric emptying and reduce nausea

›Early colonoscopy within 24 hours for hemodynamically stable patient

›Early colonoscopy within 24 hours has not demonstrated improved patient-oriented outcomes vs standard timing in all stable patients

›Within 14 days acceptable if spontaneous hemostasis achieved

›Upper endoscopy first if hemodynamically unstable or upper GI source not excluded

›10–15% of hematochezia has upper GI source

›Endoscopic hemostasis options

›Endoscopic band ligation (EBL)

›Early rebleed rate 8% vs 19% with clipping alone

›Late rebleed rate 9% vs 29% with clipping alone

›May be superior to clipping for long-term rebleed prevention

›Direct clipping (through-the-scope clips)

›Applied to stigmata of recent hemorrhage (active bleed, visible vessel, adherent clot)

›Technically challenging in right colon diverticula

›Bipolar coagulation (thermal therapy)

›Applied to actively bleeding stigmata

›Risk of full-thickness injury in thin-walled colon

Interventional radiology

›Transcatheter arterial embolization (TAE)

›Indication: CTA-positive extravasation or colonoscopy failure

›Technical success rate approximately 90%

›Clinical success (hemostasis without rebleed at 30 days) approximately 75–85%

›Embolization agents

›Microcoils or gelatin sponge for vessel occlusion

›Superselective embolization to minimize ischemic complications

›Complication risk

›Bowel ischemia: approximately 5–10% with superselective technique

›Post-embolization syndrome: fever, pain, elevation of inflammatory markers

Surgery

›Indications for surgical intervention

›Refractory hemorrhage after failed endoscopic and angiographic intervention

›Ongoing hemodynamic instability requiring continued transfusion

›Clinical judgment: massive transfusion >6 units pRBCs without source control

›Segmental colectomy if bleeding site localized by colonoscopy or CTA

›Lower rebleed rate than subtotal colectomy

›Requires confident pre-operative localization

›Subtotal colectomy with ileostomy if bleeding site not localized

›Last resort with significant morbidity

›Mortality higher in emergent surgical setting

›Preoperative optimization

›Correct coagulopathy before surgery when feasible

›Platelet transfusion if count <50 x10^9/L

›FFP or PCC for elevated INR

›Patient positioning and bowel preparation when time allows

›Cardiology clearance if recent stent with dual antiplatelet requirement

09Special Populations/sp72

Pregnancy

›Pregnancy considerations in LGIB

›Diverticular bleeding uncommon in pregnancy given younger age

›Other causes of rectal bleeding more common: hemorrhoids, fissures

›Anorectal pathology primary differential in pregnant patient with rectal bleeding

›Physiologic changes affecting assessment

›Expanded plasma volume dilutes hemoglobin baseline (physiologic anemia)

›Tachycardia may be normal in pregnancy; orthostatic changes more meaningful

›Fetal considerations

›Maternal hemodynamic stability prioritized

›Fetal heart rate monitoring when viable gestation (>24 weeks)

›Obstetric consultation early for hemodynamically unstable pregnant patient

›Imaging in pregnancy

›CTA abdomen/pelvis: use only if clinically necessary

›Fetal radiation exposure approximately 25–50 mGy with abdominal CTA

›Benefits outweigh risks in hemodynamically significant hemorrhage

›MRI pelvis without contrast preferred if time allows

›No radiation exposure; gadolinium avoided in first trimester if possible

›Colonoscopy generally safe in pregnancy when indicated

›Left lateral decubitus position preferred to avoid aortocaval compression

›Minimize CO2 insufflation time

›Medication safety

›Bowel preparation: PEG solution generally safe in pregnancy

›Avoid sodium phosphate preparations (electrolyte shifts)

›Antiemetics for colonoscopy prep: ondansetron or metoclopramide

›Metoclopramide preferred; ondansetron generally safe in second and third trimester

›Analgesia and sedation for colonoscopy: propofol and midazolam with anesthesia support

Geriatric

›Epidemiology and risk in older adults

›Diverticular bleeding predominantly affects patients >60 years

›Prevalence of diverticulosis increases from 20% at age 40 to >60% by age 80

›Age >70 is an independent predictor of new-onset diverticular bleeding

›Higher baseline antithrombotic use

›Combination antiplatelet plus anticoagulant most common in older adults

›Cardiovascular comorbidity complicates antithrombotic reversal decisions

›Atypical presentations

›Hemodynamic instability may occur without tachycardia (beta-blocker use)

›Autonomic blunting reduces heart rate response to hemorrhage

›Orthostatic hypotension more sensitive than resting tachycardia

›Cognitive impairment limits history accuracy

›Collateral history from caregivers or pharmacy essential

›Delirium may be presenting feature of hemorrhagic compromise

›Management modifications

›Restrictive transfusion threshold (Hb <70 g/L) applies but higher threshold (Hb <80 g/L) appropriate with significant cardiac disease

›Volume overload risk with rapid transfusion; consider loop diuretic

›Renal dosing adjustment for contrast agents and medications

›Estimated GFR impacts contrast nephropathy risk

›Hydration with normal saline 1 mL/kg/hr for 6 hours before and after CTA in renal impairment

›Disposition bias toward admission

›Frailty and limited home supports reduce safe discharge threshold

›Oakland score thresholds may need to be lower in frail elderly patients

Pediatrics

›Epidemiology in pediatrics

›Diverticular disease and diverticular bleeding extremely rare in children

›Colonic diverticulosis in children usually congenital and isolated

›Lower GI bleed in children warrants workup for alternative diagnoses

›Common pediatric causes of lower GI bleed

›Juvenile polyps (most common cause of painless rectal bleeding in children)

›Meckel's diverticulum with ectopic gastric mucosa

›Differential diagnosis differences in pediatrics

›Intussusception: currant jelly stool, colicky abdominal pain, palpable mass

›Peak incidence 6 months to 2 years

›Air enema or hydrostatic reduction diagnostic and therapeutic

›Inflammatory bowel disease: bloody diarrhea, weight loss, growth failure

›Meckel's diverticulum: painless rectal bleeding, often maroon

›Technetium-99m pertechnetate scan (Meckel's scan) for diagnosis

›Investigation and management approach

›Colonoscopy under general anesthesia or deep sedation in pediatric patients

›Weight-based preparation; pediatric gastroenterology involvement

›CTA dose modulation for radiation reduction

›Kilovoltage reduction and iterative reconstruction for pediatric protocols

›Consult pediatric radiology for protocol optimization

›Transfusion threshold: Hb <70 g/L in hemodynamically stable child

›Higher threshold appropriate in cardiovascular compromise or symptomatic anemia

›Volume: 10–15 mL/kg pRBCs per transfusion

10Background/b70

Epidemiology

›Prevalence and incidence

›Diverticular bleeding is the most common cause of acute LGIB

›Accounts for 30–65% of all acute lower GI bleeding episodes

›Incidence increases with age and with diverticulosis prevalence

›Diverticulosis prevalence

›Approximately 5% at age 40, increasing to >60% by age 80 in Western populations

›Cumulative hemorrhage risk from diverticulosis: 0.21% at 1 year, 2.2% at 5 years, 9.5% at 10 years

›Mortality and recurrence

›In-hospital mortality for acute LGIB approximately 3–5%

›Higher mortality in older patients with significant comorbidities

›Mortality highest with surgical intervention in emergent setting

›Spontaneous cessation approximately 70% of cases

›Recurrence: up to 40% within 4 years of first episode

›Early rebleed (within 30 days): approximately 17–24%

›Late rebleeding cumulative incidence approximately 15.7% at 5 years

›Risk factor distribution

›Right-sided diverticulosis more prevalent in Asian populations

›Left-sided predominant in Western populations

›Bilateral diverticulosis carries higher bleeding risk than either side alone

Pathophysiology

›Mechanism of diverticular hemorrhage

›Arterial bleed from vasa recta rupture

›Vasa recta travel over dome or neck of diverticulum

›Repeated injury from intraluminal contents causes asymmetric weakening of the vessel

›Not inflammatory in origin (distinct from diverticulitis)

›Bleeding arises from mechanical vascular injury

›Pain is not a primary feature; significant pain suggests diverticulitis or ischemia

›Large-volume arterial hemorrhage explains hemodynamic significance

›Unlike slow venous bleeding from hemorrhoids or angiodysplasia

›Brisk onset with rapid hemoglobin drop

›Diverticulum formation

›Colonic diverticula are pseudodiverticula (mucosal and submucosal herniation only)

›Herniation occurs at weak points where vasa recta penetrate muscularis propria

›High intraluminal pressure from low-fiber diet drives herniation

›Right-sided diverticula more often true diverticula

›Higher wall-to-lumen ratio in right colon explains different bleeding pattern

›Right-sided diverticula have larger dome diameter, increasing vascular stretch

›Contributing mechanisms for NSAIDs and antiplatelets

›NSAIDs cause mucosal ulceration at the diverticular dome and neck

›Pooled relative risk of LGIB with NSAID use approximately 1.8

›Impairs prostaglandin-mediated mucosal protection

›Antiplatelets impair hemostasis once bleeding begins

›Increases bleeding severity and duration

›P2Y12 inhibitors associated with long-term rebleeding SHR 1.24–1.32

Therapeutic Considerations

›Evidence base for colonoscopy timing

›Early colonoscopy within 24 hours vs standard timing

›Multiple RCTs have not demonstrated improved patient-oriented outcomes with early colonoscopy in hemodynamically stable patients

›ACG 2023 guideline supports colonoscopy within 24 hours for hemodynamically stable patients

›Colonoscopy within 14 days acceptable for stable patients with spontaneous hemostasis

›Bowel preparation quality impacts diagnostic yield

›Inadequate preparation reduces visualization of diverticular stigmata

›Rapid PEG preparation (4 L in 3–4 hours) preferred over split-dose in acute setting

›Endoscopic hemostasis evidence

›Endoscopic band ligation (EBL) may be superior to clipping for diverticular bleeding

›Early rebleed rate 8% vs 19% with clipping

›Late rebleed rate 9% vs 29% with clipping

›EBL technically feasible in both right and left colon diverticula

›Stigmata of recent hemorrhage (SRH) identification guides treatment

›Active bleeding, visible vessel, or adherent clot = SRH present

›Treatment of SRH reduces recurrent bleeding compared to observation

›Tranexamic acid evidence

›HALT-IT trial: tranexamic acid did not reduce death or need for transfusion in GI bleed

›Associated with increased thromboembolic events and seizure risk

›Should not be used in lower gastrointestinal bleeding (ACG 2023 guideline)

›Diverticular rebleed prevention

›No pharmacologic agent proven to prevent recurrent diverticular bleeding

›Mesalazine, rifaximin: no strong evidence for rebleed prevention

›High-fiber diet supports general colonic health but not proven to prevent rebleed

›Minimize antithrombotic exposure where clinically appropriate

›Discontinue aspirin for primary prevention permanently after diverticular bleed

›Resume antithrombotics for secondary cardiovascular prevention at earliest safe opportunity

11Patient Discharge Instructions/pdi35

copy discharge instructions

›Home care instructions

›Activity: rest for 24–48 hours after discharge

›Light activity as tolerated once feeling better

›Avoid heavy lifting or strenuous exercise for 1 week

›Diet

›Clear liquids initially, advance as tolerated

›High-fiber diet once tolerating solid foods

›Adequate hydration: 6–8 glasses of water daily

›Medications

›Take all prescribed medications as directed

›Avoid NSAIDs (ibuprofen, naproxen, diclofenac) unless specifically directed by your doctor

›Do not restart aspirin for primary prevention without discussing with your doctor

›If on anticoagulants, do not restart until instructed by your physician

›Warning signs requiring immediate return to ER

›Return immediately for recurrence of blood in stool (any amount)

›Bright red blood, dark red blood, or maroon-colored stool

›Passage of blood clots

›Lightheadedness, dizziness, or fainting

›Rapid heart rate or palpitations

›Weakness or inability to stand

›Chest pain or shortness of breath

›New or worsening abdominal pain

›Significant nausea or vomiting preventing hydration

›Fever above 38.5 C (101.3 F)

›Decreased urine output or signs of dehydration

›Follow-up instructions

›Outpatient colonoscopy within 14 days if not performed during hospital stay

12References/r24

Guidelines and key sources

›ACG guidelines

›Sengupta N, Feuerstein JD, Jairath V, et al. Management of Patients With Acute Lower Gastrointestinal Bleeding: An Updated ACG Guideline. Am J Gastroenterol. 2023

›Oakland score validation and use for LGIB risk stratification

›Colonoscopy timing, endoscopic hemostasis, and antithrombotic management

›ACR Appropriateness Criteria: Radiologic Management of Lower Gastrointestinal Tract Bleeding: 2021 Update. Karuppasamy K et al. J Am Coll Radiol. 2021

›CTA as first-line imaging for hemodynamically significant LGIB

›Landmark reviews and trials

›Gralnek IM, Neeman Z, Strate LL. Acute Lower Gastrointestinal Bleeding. NEJM. 2017

›Comprehensive review of epidemiology, diagnosis, and management of LGIB

›Long B, Gottlieb M. Emergency Medicine Updates: Lower Gastrointestinal Bleeding. Am J Emerg Med. 2024

›Emergency department focused review and management update

›HALT-IT Trial: tranexamic acid in GI bleeding. Lancet. 2020

›Tranexamic acid does not reduce mortality; associated with increased adverse events

›Diverticular disease specific

›Tursi A et al. Revised Version Global Guidelines on Diverticular Disease of the Colon: The Fiesole Consensus Report. Gut. 2025

›Global consensus on diverticular disease management

›Wangrattanapranee P, Khrucharoen U, Jensen DM, Jensen ME. Long-Term Natural History of Presumptive Diverticular Hemorrhage. Am J Gastroenterol. 2024

›Long-term recurrence rates and natural history data

›Sato Y et al. Long-Term Risks of Recurrence After Hospital Discharge for Acute Lower Gastrointestinal Bleeding. Clin Gastroenterol Hepatol. 2023

›Late rebleeding cumulative incidence and risk factor analysis

›ICD-10 coding

›ICD-10 K57.31 diverticulosis of large intestine without perforation or abscess with bleeding

›ICD-10 K92.1 melena

›ICD-10 K92.2 gastrointestinal hemorrhage unspecified

Evidence & Review

Evidence & Review