Management of colonic diverticular bleeding: A narrative review with literature search of current evidence and therapeutic strategies

Table 1 Risk factors for colonic diverticular bleeding

Category	Risk factors	Effect size/notes
Patient/anatomic	Age > 70 years	HR: 1.5-2.0; independent predictor of new-onset CDB
	Bilateral diverticulosis (right + left)	Key predictor of onset; higher cumulative incidence
	Hypertension/atherosclerosis	Contributes to vascular fragility of vasa recta
NSAIDs	Non-selective NSAIDs	OR = 6.90 (95%CI: 3.86-12.35); Longo et al[17] meta-analysis
	Aspirin (any dose)	OR = 2.84 (95%CI: 2.19-3.67)
	COX-2 selective inhibitors	Not associated with increased CDB risk
Antiplatelets	P2Y12 inhibitors (clopidogrel)	Increased LGIB risk; limited CDB-specific data
Anticoagulants	Vitamin K antagonists (warfarin)	Approximately 3-fold increased GI bleeding vs placebo
	Rivaroxaban vs apixaban	HR = 1.53 (95%CI: 1.00-2.33) higher LGIB risk with rivaroxaban
	DOACs vs antiplatelets	DOACs not shown to increase new-onset CDB
Combination	Dual antiplatelet + anticoagulant	Incidence approximately 70/1000 person-years
	Triple antithrombotic therapy	Highest risk combination; avoid when possible

GI: Gastrointestinal; NSAIDs: Non-steroidal anti-inflammatory drugs; HR: Hazard ratio; CDB: Colonic diverticular bleeding; COX-2: Cyclooxygenase-2; DOAC: Direct oral anticoagulant; OR: Odds ratio; CI: Confidence interval; LGIB: Lower gastrointestinal bleeding.

Table 2 Oakland score variables and discharge threshold

Variable	Category	Points	Interpretation
Age	< 40 years	0
	40-69 years	1
	≥ 70 years	2
Sex	Female	0
	Male	1
Prior LGIB	No	0
	Yes	1
DRE	No blood	0
	Blood	1
Heart rate	≤ 70 bpm	0
	71-89 bpm	1
	90-109 bpm	2
	≥ 110 bpm	3
Systolic BP	≥ 160 mmHg	0
	130-159 mmHg	1
	100-129 mmHg	2
	50-99 mmHg	3
Hemoglobin	≥ 16.0 g/dL	0
	13.0-15.9 g/dL	1
	11.0-12.9 g/dL	2
	9.0-10.9 g/dL	3
	6.0-8.9 g/dL	4
	< 6.0 g/dL	5
Score ≤ 8	≥ 95% probability of safe discharge; ESGE and BSG recommend outpatient evaluation

A score ≤ 8 predicts a ≥ 95% probability of safe discharge (area under the receiver-operating characteristic curve = 0.87). LGIB: Lower gastrointestinal bleeding; DRE: Digital rectal examination; BP: Blood pressure; ESGE: European Society of Gastrointestinal Endoscopy; BSG: British Society of Gastroenterology.

Table 3 Transfusion strategy: Evidence base and guideline recommendations

Domain	Study/threshold	Key finding/recommendation
Hb threshold	7 g/dL (restrictive)	Standard recommendation for hemodynamically stable LGIB
	8 g/dL	Reasonable in significant cardiovascular disease
	Before Hb < 7 if hypotensive	Dilutional drop post-resuscitation underestimates deficit; transfuse early
UGIB RCT evidence	Villanueva et al[21] (n = 921)	Restrictive: Improved 6-week survival, lower rebleeding vs liberal
	Meta-analysis 5 RCTs (n = 1965)	Restrictive: RR mortality 0.65 (0.44-0.97); Rebleeding RR 0.58 (0.40-0.84)
	Teutsch et al[24] meta-analysis (7 RCTs)	Restrictive did not increase in-hospital or 30-day mortality
LGIB data	United Kingdom audit post hoc analysis	No significant difference in rebleeding or mortality between strategies; post hoc, underpowered
Guidelines	AABB 2023 International Guidelines[27]	Restrictive strategy recommended across clinical settings
	ACG, ESGE, BSG	Hb 7 g/dL stable patients; 8 g/dL in CVD; early transfusion if hemodynamically unstable

Evidence for lower gastrointestinal bleeding is largely extrapolated from upper gastrointestinal bleeding trials; dedicated lower gastrointestinal bleeding transfusion randomized controlled trials are needed. Hb: Hemoglobin; UGIB: Upper gastrointestinal bleeding; RCT: Randomized controlled trial; LGIB: Lower gastrointestinal bleeding; AABB: American Association of Blood Banks; ACG: American College of Gastroenterology; ESGE: European Society of Gastrointestinal Endoscopy; BSG: British Society of Gastroenterology; CVD: Cardiovascular disease; RR: Relative risk.

Table 4 Key definitions used throughout this narrative review

Term	Definition
Definitive CDB	Colonic diverticular bleeding with endoscopic identification of stigmata of recent hemorrhage (SRH) at a diverticulum, or active bleeding observed during colonoscopy or angiography
Presumptive CDB	Suspected diverticular hemorrhage in a patient with diverticulosis identified at colonoscopy but without SRH or active bleeding at the diverticulum, after exclusion of other LGIB sources
Stigmata of recent hemorrhage (SRH)	Endoscopic findings indicative of recent bleeding, including active spurting/oozing bleeding, non-bleeding visible vessel, adherent clot, or flat pigmented spot at the diverticulum
Successful endoscopic hemostasis	Cessation of active bleeding and absence of recurrent bleeding during the index colonoscopy, with no clinical or laboratory evidence of ongoing hemorrhage
Early rebleeding	Recurrent hematochezia or hemodynamic instability within 30 days of initial hemostasis, requiring repeat intervention or hospitalization
Late rebleeding	Recurrent diverticular hemorrhage occurring beyond 30 days of the index episode, typically reported at 90 days, 365 days, or longer cumulative intervals
Technical success (TAE)	Successful catheterization of the bleeding vessel with deployment of embolic material and angiographic cessation of extravasation
Clinical success (TAE)	Absence of recurrent bleeding within 30 days following the procedure, with no requirement for additional intervention
Hemodynamic instability	Shock index (HR/SBP) > 1, persistent hypotension despite resuscitation, or ongoing transfusion requirement

CDB: Colonic diverticular bleeding; SRH: Stigmata of recent hemorrhage; TAE: Transcatheter arterial embolization; LGIB: Lower gastrointestinal bleeding; HR: Heart rate; SBP: Systolic blood pressure.

Table 5 Classification of stigmata of recent hemorrhage in colonic diverticular bleeding

Stigmata category	Endoscopic appearance	Rebleeding risk	Management implications
Active spurting bleeding	Pulsatile arterial bleeding from the diverticular neck or dome	Highest	Active bleeding present; mandatory endoscopic hemostasis
Active oozing bleeding	Non-pulsatile slow bleeding from the diverticulum	High	Endoscopic hemostasis indicated
Non-bleeding visible vessel	Pigmented protuberant lesion within the diverticulum without active bleeding	High	Endoscopic hemostasis recommended
Adherent clot	Clot tightly adherent to the diverticulum despite irrigation	Moderate	Consider removal and treatment; controversial
Flat pigmented spot	Black or red discoloration without protrusion, no active bleeding or clot	Lower	No proven benefit from endoscopic therapy; observation appropriate
Clean-based diverticulum (no SRH)	Diverticulum without stigmata in a patient with presumptive CDB	Lowest	Conservative management; consider further investigation

This classification was synthesized by the authors from criteria and outcome data reported in the CODE-BLUE J-study[7] and current society guidelines[5]; it is an original synthesis, not a reproduction of a single previously published table, and therefore does not require copyright permission. SRH: Stigmata of recent hemorrhage; CDB: Colonic diverticular bleeding.

Table 6 Comparison of endoscopic hemostatic modalities for colonic diverticular bleeding (revised)

Outcome	EBL	TTS clip (direct)	OTSC	Evidence base and quality
Initial hemostasis	93%-100%	95%-100%	Approximately 95%-100%	All modalities equivalent; pooled 98.9% (Meine et al[30], 21 studies, 3161 pts)
Early rebleeding (≤ 30 days)	8%	19%	OR 0.16 vs EBL (PSM cohort, n = 303)	EBL vs TTS: Nagata et al[31], 16 studies/790 pts, P = 0.012; CODE-BLUE J[7]: 1679 pts, aOR = 0.46; OTSC: Ohashi et al[32]
Late rebleeding (≤ 1 year)	9%	29%	Not yet reported	EBL vs TTS: Nagata et al[31], P = 0.024; CODE-BLUE J[7]: AOR = 0.62
Need for TAE/surgery	1%	2% (P = 0.031 vs EBL)	0% (single-center, n = 36)	CODE-BLUE J[7]: AOR = 0.37, P = 0.006; Meine et al[30]
Adverse events	Perforation 0.31%; diverticulitis 0.16%	Perforation 0%; diverticulitis 0.19%	0% (limited data)	CODE-BLUE J[7]: 1679 pts; OTSC: Very limited n
Length of stay	Shorter (aOR = 0.35 vs clip, P < 0.001)	Reference	Shorter vs EBL (P = 0.026)	CODE-BLUE J[7]; Ohashi et al[32]
Number of supporting studies	2 meta-analyses + CODE-BLUE J (638 EBL pts)[5,7,35]	Largest volume: CODE-BLUE J 1041 clip pts[7]; all meta-analyses	1 PSM cohort (n = 303)[32]; 1 single-center (n = 36); case reports
Overall quality of evidence	Moderate: Meta-analyses of observational data + large multicenter retrospective cohort; No RCTs; Predominantly Japanese data	Moderate: Same evidence base; Globally established technique	Very low: 1 small PSM retrospective study; No RCTs

No randomized controlled trials exist comparing these modalities. All evidence derives from observational studies and retrospective cohorts. Endoscopic band ligation data derive predominantly from Japanese cohorts with right-sided diverticulosis predominance; generalizability to Western populations with left-sided disease requires prospective validation. EBL: Endoscopic band ligation; TTS: Through-the-scope; OTSC: Over-the-scope clip; TAE: Transcatheter arterial embolization; aOR: Adjusted odds ratio; pts: Patients; RCT: Randomized controlled trial; PSM: Propensity score matched.

Table 7 Pooled outcomes from meta-analyses of transcatheter arterial embolization for lower gastrointestinal bleeding

Study/agent	Technical success	Clinical success	30-day rebleeding	30-day mortality	Notes
NBCA embolization (SR/MA, n = 243)	98.8%		15.7%	12.7%	Highest technical success of agent subgroups
Matsumoto et al[10] (NBCA or coils)	91.4%	76.5%	17.1%	11.4%	Major complication 10.0%; LGIB subgroup
Sun et al[11] (n = 58 trials, 3530)	90.4%	73.5%	19.9%	9.6%	Largest meta-analysis to date
Superselective TAE	93.4%		16.9%		vs non-super selective: TS 93.4% vs 85.3%; rebleed 16.9% vs 26.6%
Kitamura et al[36] (n = 132)	72% CTA positive	67% TAE performed	3.4% vs 30% (P < 0.001)	0%	Right-sided TAE particularly effective; no deaths

NBCA: N-butyl cyanoacrylate; SR/MA: Systematic review/meta-analysis; TAE: Transcatheter arterial embolization; CTA: Computed tomographic angiography; LGIB: Lower gastrointestinal bleeding; TS: Technical success.

Table 8 Indications for surgical intervention in colonic diverticular bleeding and operative strategy selection

Surgical indication/operative strategy	Clinical context/selection principle
Hemodynamic instability refractory to resuscitation	Requires massive transfusion; endoscopic/IR hemostasis not feasible or failed
Transfusion > 10 units pRBC with identified colonic source	Ongoing hemorrhage despite non-operative management
Failed endoscopic and TAE hemostasis	Salvage colectomy; segment identification by intraoperative colonoscopy if feasible
Recurrent life-threatening hemorrhage (localized source)	Elective laparoscopic segmental colectomy preferred
Perforation or surgical complication	Emergent laparotomy; bowel viability assessment required
Segmental colectomy	Preferred when source confirmed by CTA or colonoscopy; lower morbidity, better functional outcome
Total abdominal colectomy (TAC)	Reserved for unlocalized bleeding; 0% rebleeding but significant diarrhea/incontinence rates

pRBC: Packed red blood cells; TAE: Transcatheter arterial embolization; TAC: Total abdominal colectomy; CTA: Computed tomographic angiography; IR: Interventional radiology.

Table 9 Framework for antithrombotic management after colonic diverticular bleeding

Agent/class	TE risk if stopped	Resumption timing	Clinical considerations
Anticoagulation (high TE risk)	High	7-14 days post-hemostasis	Earlier (< 7 days) for mechanical valves, recent stroke
Anticoagulation (AF)	High	≤ 7 days preferred	Lower MACE without significant increase in GI rebleeding in AF
Warfarin	Varies	After INR therapeutic	Use 4F-PCC (not FFP) for urgent reversal
Rivaroxaban	Moderate	Consider switch to apixaban	HR 1.53 higher LGIB risk vs apixaban; class switch reasonable
Aspirin (2° CV prevention)	High if stopped	Resume as soon as feasible	Discontinuation increases mortality; rebleeding risk outweighed
DAPT (recent PCI/ACS)	Very high if stopped	Continue aspirin; liaise cardiology re P2Y12	P2Y12 pause per stent age; never stop both without cardiology input
NSAIDs	Low (TE)	Substitute if possible	Replace with acetaminophen or COX-2 inhibitor where feasible
Andexanet alfa (factor Xa reversal)			Withdrawn from United States market; confirm availability with pharmacy/hematology

Resumption timing recommendations are based on observational data only; no randomized controlled trials exist. TE: Thromboembolic; AF: Atrial fibrillation; CV: Cardiovascular; DAPT: Dual antiplatelet therapy; PCI: Percutaneous coronary intervention; ACS: Acute coronary syndrome; NSAIDs: Non-steroidal anti-inflammatory drugs; INR: International normalized ratio; MACE: Major adverse cardiovascular events; GI: Gastrointestinal; 4F-PCC: Four-factor prothrombin complex concentrate; FFP: Fresh frozen plasma; HR: Hazard ratio; COX-2: Cyclooxygenase-2; LGIB: Lower gastrointestinal bleeding.

Table 10 Summary of key clinical questions, supporting evidence, study types, quality of evidence, and strength of recommendation

Clinical question	Supporting evidence	Study types	Quality of evidence	Strength of recommendation
Transfusion threshold (Hb 7 g/dL stable LGIB)	Villanueva RCT; 5-RCT meta-analysis; United Kingdom LGIB audit post hoc	2 RCTs (UGIB); 1 post hoc LGIB analysis	Moderate extrapolated from UGIB; LGIB-specific data very limited	Conditional 7 g/dL; 8 g/dL in CVD
CTA first in hemodynamically unstable patients	Meta-analysis 14 studies (90% sensitivity, 92% specificity); ACG-SAR consensus[14]	Systematic review; consensus guideline	Moderate	Strong
Elective colonoscopy (not urgent) for stable patients	Niikura et al[9] RCT (n = 170); second RCT (increased rebleeding with early scope)	2 RCTs	Moderate	Conditional urgent only in selected high-risk patients
EBL preferred over TTS clipping	Nagata et al[31] meta-analysis; CODE-BLUE J[7]; Meine et al[30]	Meta-analyses of observational data; large multicenter retrospective cohort	Moderate no RCTs; predominantly Japanese data	Conditional EBL may be preferred; prospective Western trials needed
OTSC as alternative to EBL	Ohashi et al[32]: PSM cohort n = 303; 1 single-center series	1 PSM retrospective cohort; 1 case series	Very low	Emerging insufficient evidence for routine use
TAE for failed endoscopy or active CTA extravasation	Sun et al[11]: 58 trials/3530 pts; Kitamura et al[36]	Meta-analysis + retrospective cohort	Moderate	Strong as salvage; conditional as primary
Antithrombotic resumption within 7-14 days (high TE risk)	Sengupta et al[5] retrospective cohort, 1329 pts	Retrospective cohort only; no RCTs	Low	Conditional individualize TE vs rebleeding risk
Elective colectomy for recurrent localized CDB	ACG guideline[5]; retrospective comparative series; You et al[37]; Vajravelu et al[38]; Sato et al[39]	Guideline; retrospective series; cohort studies	Low	Conditional after 2 + episodes, localized source, suitable candidate

Hb: Hemoglobin; LGIB: Lower gastrointestinal bleeding; CTA: Computed tomographic angiography; EBL: Endoscopic band ligation; TTS: Through-the-scope; OTSC: Over-the-scope clip; TAE: Transcatheter arterial embolization; TE: Thromboembolic; CDB: Colonic diverticular bleeding; RCT: Randomized controlled trial; ACG: American College of Gastroenterology; SAR: Society of Abdominal Radiology; PSM: Propensity score matched; pts: Patients; UGIB: Upper gastrointestinal bleeding; CVD: Cardiovascular disease.