Identifying Bleeding Etiologies by Endoscopy Affected Outcomes in 10,342 Cases With Hematochezia: CODE BLUE-J Study

Appendicitis after endoscopic band ligation for massive ileocecal hemorrhage

A 68-year-old man was admitted with hematochezia. Emergency computed tomography showed multiple diverticula throughout the colon. Initial colonoscopy on day 2 showed no active bleeding, but massive hematochezia on day 3 led to the performance of an emergency endoscopy. Substantial bleeding in the ileocecal area obscured the visual field, making it challenging to view the area around the bleeding site. Two endoscopic band ligations (EBLs) were applied at the suspected bleeding sites. Hemostasis was achieved without active bleeding after EBL. However, the patient developed lower right abdominal pain and fever (39.4°C) on day 6. Urgent computed tomography revealed appendiceal inflammation, necessitating emergency open ileocecal resection for acute appendicitis. Pathological examination confirmed acute phlegmonous appendicitis, with EBLs noted at the appendiceal orifice and on the anal side. This case illustrates the efficacy of EBL in managing colonic diverticular bleeding. However, it also highlights the risk of appendicitis due to EBL in cases of ileocecal hemorrhage exacerbated by poor visibility due to substantial bleeding. Endoscopists need to consider this rare but important complication when performing EBL in similar situations.

Emergency medicine updates: Lower gastrointestinal bleeding

INTRODUCTION

Lower gastrointestinal bleeding (LGIB) is a condition commonly seen in the emergency department. Therefore, it is important for emergency medicine clinicians to be aware of the current evidence regarding the diagnosis and management of this disease.

OBJECTIVE

This paper evaluates key evidence-based updates concerning LGIB for the emergency clinician.

DISCUSSION

LGIB is most commonly due to diverticulosis or anorectal disease, though there are a variety of etiologies. The majority of cases resolve spontaneously, but patients can have severe bleeding resulting in hemodynamic instability. Initial evaluation should focus on patient hemodynamics, the severity of bleeding, and differentiating upper gastrointestinal bleeding from LGIB. Factors associated with LGIB include prior history of LGIB, age over 50 years, and presence of blood clots per rectum. Computed tomography angiography is the imaging modality of choice in those with severe bleeding to diagnose the source of bleeding and guide management when embolization is indicated. Among stable patients without severe bleeding, colonoscopy is the recommended modality for diagnosis and management. A transfusion threshold of 7 g/dL hemoglobin is recommended based on recent data and guidelines (8 g/dL in those with myocardial ischemia), though patients with severe bleeding and hemodynamic instability should undergo emergent transfusion. Anticoagulation reversal may be necessary. If bleeding does not resolve, embolization or endoscopic therapies are necessary. There are several risk scores that can predict the risk of adverse outcomes; however, these scores should not replace clinical judgment in determining patient disposition.

CONCLUSIONS

An understanding of literature updates can improve the care of patients with LGIB.

Association of blood group O with a recurrent risk for acute lower gastrointestinal bleeding from a multicenter cohort study

The relationship between blood group and rebleeding in acute lower gastrointestinal bleeding (ALGIB) remains unclear. This study aimed to investigate the association between blood group O and clinical outcomes in patients with ALGIB. The study included 2336 patients with ALGIB whose bleeding source was identified during initial endoscopy (from the CODE BLUE-J Study). The assessed outcomes encompassed rebleeding and other clinical parameters. The rebleeding rates within 30 days in patients with blood group O and those without blood group O were 17.9% and 14.9%, respectively. Similarly, the rates within 1 year were 21.9% for patients with blood group O and 18.2% for those without blood group O. In a multivariate analysis using age, sex, vital signs at presentation, blood test findings, comorbidities, antithrombotic medication, active bleeding, and type of endoscopic treatment as covariates, patients with blood group O exhibited significantly higher risks for rebleeding within 30 days (odds ratio [OR] 1.31; 95% confidence interval [CI] 1.04-1.65; P = 0.024) and 1 year (OR 1.29; 95% CI 1.04-1.61; P = 0.020) compared to those without blood group O. However, the thrombosis and mortality rates did not differ significantly between blood group O and non-O patients. In patients with ALGIB, blood group O has been identified as an independent risk factor for both short- and long-term rebleeding.

Usefulness of a long hood for the detection of bleeding sites in colonic diverticular hemorrhage: A randomized controlled trial

Background and Aim

The use of a hood at the tip of a colonoscope enables aspiration, inversion of the diverticulum, and observation of the inside of the diverticulum. In most previous studies, a short hood was used; however, observation of the diverticulum is often inadequate. Long food is promising by previous research, but it was a retrospective study using propensity matching and has some limitations. We compared the identification rate of stigmata of recent hemorrhage (SRH) between the long and standard hoods in cases of suspected colonic diverticular hemorrhage (CDH) to confirm the usefulness of long hood by prospective randomized controlled trial.

Methods

Eighty patients (42 in the long hood group [L group] and 38 in the short hood group [S group]) who visited the Saitama Medical University Hospital and Tokai University Hachioji Hospital between December 2018 and July 2021 with a chief complaint of bloody stool and suspected CDH, based on the clinical course and imaging studies, were included. Patients were randomly assigned to the L or S group.

Results

Regarding patient background, age was significantly higher in the L group; however, no significant differences were found in medical history or history of antithrombotic medication or nonsteroidal anti-inflammatory drug use. Identification rate of SRH was significantly higher in the L group (58.5%, 24/42 patients) than in the S group (26.3%, 10/38 patients) (P < 0.05). All patients were treated using the clip method, and the rate of rebleeding within 1 month was not significantly different between the two groups.

Conclusion

A long hood was more useful compared with a short hood in identifying SRH of CDH (UMIN000034603).

Colonic diverticular bleeding due to a rupture of an ileocolic artery pseudoaneurysm secondary to colonic diverticulitis

A 53-year-old woman with a history of recurrent right lower quadrant pain presented with slightly bloody stools in April 2023. She was initially diagnosed with acute diverticulitis using an abdominal computed tomography (CT) scan and was treated conservatively. On the second day, however, she reported significant hematochezia. A subsequent contrast-enhanced CT scan revealed an extravasation in the ascending colon, which was promptly managed with colonoscopy. Despite initial hemostasis, she experienced recurrent bleeding. Another contrast-enhanced CT scan revealed a pseudoaneurysm with ongoing extravasation in the same area. Angiography confirmed a pseudoaneurysm in a branch of the ileocolic artery, which was successfully treated by embolization. She was discharged after an 18 day hospital stay. This case highlights a pseudoaneurysm caused by diverticulitis.

Advances in endoscopic management of colonic diverticular bleeding

PURPOSE OF REVIEW

This review is focused on diagnostic and management strategies for colonic diverticular bleeding (CDB). It aims to present the current state of the field, highlighting the available techniques, and emphasizing findings that influence the choice of therapy.

RECENT FINDINGS

Recent guidelines recommend nonurgent colonoscopy (>24 h) for CDB. However, factors such as a shock index ≥1, which may warrant an urgent colonoscopy, remain under investigation.The standard approach to detecting the source of CDB requires a water-jet scope equipped with a cap. Innovative diagnostic techniques, such as the long-cap and tapered-cap, have proven effective in identifying stigmata of recent hemorrhage (SRH). Furthermore, the water or gel immersion methods may aid in managing massive hemorrhage by improving the visualization and stabilization of the bleeding site for subsequent intervention. Innovations in endoscopic hemostasis have significantly improved the management of CDB. New therapeutic methods such as endoscopic band ligation and direct clipping have substantially diminished the incidence of recurrent bleeding. Recent reports also have demonstrated the efficacy of cutting-edge techniques such as over-the-scope clips, which have significantly improved outcomes in complex cases that have historically necessitated surgical intervention.

SUMMARY

Currently available endoscopic diagnostic and hemostatic methods for CDB have evolved with improved outcomes. Further research is necessary to refine the criteria for urgent colonoscopy and to confirm the effectiveness of new endoscopic hemostasis techniques.

Is bowel preparation necessary for early colonoscopy in patients with suspected colonic diverticular bleeding?: A multicenter retrospective study with propensity score matching analysis

Objectives

There are few reports on bowel preparation for early colonoscopy in patients with suspected colonic diverticular bleeding (CDB). We aim to clarify in a retrospective, multicenter study.

Methods

In a multicenter retrospective cohort study at 10 institutions, we analyzed clinical features of patients diagnosed with CDB, who underwent early colonoscopy within 24 h. We compared patients who were prepared with polyethylene glycol lavage (PEL) and those without PEL. We evaluated the effects of PEL for early colonoscopy in patients with suspected CDB.

Results

A total of 129 (53%) underwent under preparation with PEL and 113 patients without PEL. The PEL group was younger, had fewer comorbidities, and had better performance status. After adjusting for these variables with propensity score matching, the PEL group had a significantly shorter hospital stay (7.9 ± 4.7 vs. 10.1 ± 5.2 days; p = 0.001), and a higher cecal intubation rate (91.1% vs. 50.0%; p < 0.001). There were no significant differences in adverse event rates, identification of stigmata of recent hemorrhage, or frequency in endoscopic hemostatic treatment.

Conclusions

PEL may be preferred for early colonoscopy in patients suspected of having CDB.

High risk stigmata and treatment strategy for acute lower gastrointestinal bleeding: a nationwide study in Japan

BACKGROUND

 The rebleeding risks and outcomes of endoscopic treatment for acute lower gastrointestinal bleeding (ALGIB) may differ depending on the bleeding location, type, and etiology of stigmata of recent hemorrhage (SRH) but have yet to be fully investigated. We aimed to identify high risk endoscopic SRH and to propose an optimal endoscopic treatment strategy.

METHODS

 We retrospectively analyzed 2699 ALGIB patients with SRH at 49 hospitals (CODE BLUE-J Study), of whom 88.6 % received endoscopic treatment.

RESULTS

 30-day rebleeding rates of untreated SRH significantly differed among locations (left colon 15.5 % vs. right colon 28.6 %) and etiologies (diverticular bleeding 27.5 % vs. others [e. g. ulcerative lesions or angioectasia] 8.9 %), but not among bleeding types. Endoscopic treatment reduced the overall rebleeding rate (adjusted odds ratio [AOR] 0.69; 95 %CI 0.49-0.98), and the treatment effect was significant in right-colon SRH (AOR 0.46; 95 %CI 0.29-0.72) but not in left-colon SRH. The effect was observed in both active and nonactive types, but was not statistically significant. Moreover, the effect was significant for diverticular bleeding (AOR 0.60; 95 %CI 0.41-0.88) but not for other diseases. When focusing on treatment type, the effectiveness was not significantly different between clipping and other modalities for most SRH, whereas ligation was significantly more effective than clipping in right-colon diverticular bleeding.

CONCLUSIONS

 A population-level endoscopy dataset allowed us to identify high risk endoscopic SRH and propose a simple endoscopic treatment strategy for ALGIB. Unlike upper gastrointestinal bleeding, the rebleeding risks for ALGIB depend on colonic location, bleeding etiology, and treatment modality.

A novel prediction tool for mortality in patients with acute lower gastrointestinal bleeding requiring emergency hospitalization: a large multicenter study

The study aimed to identify prognostic factors for patients with acute lower gastrointestinal bleeding and to develop a high-accuracy prediction tool. The analysis included 8254 cases of acute hematochezia patients who were admitted urgently based on the judgment of emergency physicians or gastroenterology consultants (from the CODE BLUE J-study). Patients were randomly assigned to a derivation cohort and a validation cohort in a 2:1 ratio using a random number table. Assuming that factors present at the time of admission are involved in mortality within 30 days of admission, and adding management factors during hospitalization to the factors at the time of admission for mortality within 1 year, prognostic factors were established. Multivariate analysis was conducted, and scores were assigned to each factor using regression coefficients, summing these to measure the score. The newly created score (CACHEXIA score) became a tool capable of measuring both mortality within 30 days (ROC-AUC 0.93) and within 1 year (C-index, 0.88). The 1-year mortality rates for patients classified as low, medium, and high risk by the CACHEXIA score were 1.0%, 13.4%, and 54.3% respectively (all P < 0.001). After discharge, patients identified as high risk using our unique predictive score require ongoing observation.

Review article: Advances in the management of lower gastrointestinal bleeding

BACKGROUND

Lower gastrointestinal bleeding (LGIB) is a common emergency with substantial associated morbidity and mortality. Elective colonoscopy plays an essential role in management, with an even more important role for radiology in the acute setting. Recent advances in the management of patients with LGIB warrant review as the management has recently evolved.

AIMS

To provide a comprehensive and updated overview of advances in the approach to patients with LGIB METHODS: We performed a comprehensive literature search to examine the current data for this narrative review supplemented by expert opinion.

RESULTS

The incidence of LGIB is increasing worldwide, partly related to an ageing population and the increasing use of antithrombotics. Diverticulosis continues to be the most common aetiology of LGIB. Pre-endoscopic risk stratification tools, especially the Oakland score, can aid appropriate patient triage. Adequate resuscitation continues to form the basis of management, while appropriate management of antithrombotics is crucial to balance the risk of worsening bleeding against increased cardiovascular risk. Radiological imaging plays an essential role in the diagnosis and treatment of acute LGIB, especially among unstable patients. Colonoscopy remains the gold-standard test for the elective management of stable patients.

CONCLUSIONS

The management of LGIB has evolved significantly in recent years, with a shift towards radiological interventions for unstable patients while reserving elective colonoscopy for stable patients. A multidisciplinary approach is essential to optimise the outcomes of patients with LGIB.

Diagnosis and management of acute lower gastrointestinal bleeding

PURPOSE OF REVIEW

We review and summarize the most recent literature, including evidence-based guidelines, on the evaluation and management of acute lower gastrointestinal bleeding (LGIB).

RECENT FINDINGS

LGIB primarily presents in the elderly, often on the background of comorbidities, and constitutes a significant healthcare and economic burden worldwide. Therefore, acute LGIB requires rapid evaluation, informed decision-making, and evidence-based management decisions. LGIB management involves withholding and possibly reversing precipitating medications and concurrently addressing risk factors, with definitive diagnosis and therapy for the source of bleeding usually performed by endoscopic or radiological means. Recent advancements in LGIB diagnosis and management, including risk stratification tools and novel endoscopic therapeutic techniques have improved LGIB management and patient outcomes. In recent years, the various society guidelines on acute lower gastrointestinal bleeding have been revised and updated accordingly.

SUMMARY

By integrating the most recently published high-quality clinical studies and society guidelines, we provide clinicians with an up-to-date and comprehensive overview on acute LGIB diagnosis and management.

Characteristics, outcomes, and risk factors of surgery for acute lower gastrointestinal bleeding: nationwide cohort study of 10,342 hematochezia cases

BACKGROUND

Current evidence on the surgical rate, indication, procedure, risk factors, mortality, and postoperative rebleeding for acute lower gastrointestinal bleeding (ALGIB) is limited.

METHODS

We constructed a retrospective cohort of 10,342 patients admitted for acute hematochezia at 49 hospitals (CODE BLUE J-Study) and evaluated clinical data on the surgeries performed.

RESULTS

Surgery was performed in 1.3% (136/10342) of the cohort with high rates of colonoscopy (87.7%) and endoscopic hemostasis (26.7%). Indications for surgery included colonic diverticular bleeding (24%), colorectal cancer (22%), and small bowel bleeding (16%). Sixty-four percent of surgeries were for hemostasis for severe refractory bleeding. Postoperative rebleeding rates were 22% in patients with presumptive or obscure preoperative identification of the bleeding source and 12% in those with definitive identification. Thirty-day mortality rates were 1.5% and 0.8% in patients with and without surgery, respectively. Multivariate analysis showed that surgery-related risk factors were transfusion need ≥ 6 units (P < 0.001), in-hospital rebleeding (P < 0.001), small bowel bleeding (P < 0.001), colorectal cancer (P < 0.001), and hemorrhoids (P < 0.001). Endoscopic hemostasis was negatively associated with surgery (P = 0.003). For small bowel bleeding, the surgery rate was significantly lower in patients with endoscopic hemostasis as 2% compared to 12% without endoscopic hemostasis.

CONCLUSIONS

Our cohort study elucidated the outcomes and risks of the surgery. Extensive exploration including the small bowel to identify the source of bleeding and endoscopic hemostasis may reduce unnecessary surgery and improve the management of ALGIB.

Long-term Risks of Recurrence After Hospital Discharge for Acute Lower Gastrointestinal Bleeding: A Large Nationwide Cohort Study

BACKGROUND & AIMS

Currently, large, nationwide, long-term follow-up data on acute lower gastrointestinal bleeding (ALGIB) are scarce. We investigated long-term risks of recurrence after hospital discharge for ALGIB using a large multicenter dataset.

METHODS

We retrospectively analyzed 5048 patients who were urgently hospitalized for ALGIB at 49 hospitals across Japan (CODE BLUE-J study). Risk factors for the long-term recurrence of ALGIB were analyzed by using competing risk analysis, treating death without rebleeding as a competing risk.

RESULTS

Rebleeding occurred in 1304 patients (25.8%) during a mean follow-up period of 31 months. The cumulative incidences of rebleeding at 1 and 5 years were 15.1% and 25.1%, respectively. The mortality risk was significantly higher in patients with out-of-hospital rebleeding episodes than in those without (hazard ratio, 1.42). Of the 30 factors, multivariate analysis showed that shock index ≥1 (subdistribution hazard ratio [SHR], 1.25), blood transfusion (SHR, 1.26), in-hospital rebleeding (SHR, 1.26), colonic diverticular bleeding (SHR, 2.38), and thienopyridine use (SHR, 1.24) were significantly associated with increased rebleeding risk. Multivariate analysis of colonic diverticular bleeding patients showed that blood transfusion (SHR, 1.20), in-hospital rebleeding (SHR, 1.30), and thienopyridine use (SHR, 1.32) were significantly associated with increased rebleeding risk, whereas endoscopic hemostasis (SHR, 0.83) significantly decreased the risk.

CONCLUSIONS

These large, nationwide follow-up data highlighted the importance of endoscopic diagnosis and treatment during hospitalization and the assessment of the need for ongoing thienopyridine use to reduce the risk of out-of-hospital rebleeding. This information also aids in the identification of patients at high risk of rebleeding.

Early feeding reduces length of hospital stay in patients with acute lower gastrointestinal bleeding: A large multicentre cohort study

AIM

No studies have compared the clinical outcomes of early and delayed feeding in patients with acute lower gastrointestinal bleeding (ALGIB). This study aimed to evaluate the benefits and risks of early feeding in a nationwide cohort of patients with ALGIB in whom haemostasis was achieved.

METHODS

We reviewed data for 5910 patients with ALGIB in whom haemostasis was achieved and feeding was resumed within 3 days after colonoscopy at 49 hospitals across Japan (CODE BLUE-J Study). Patients were divided into an early feeding group (≤1 day, n = 3324) and a delayed feeding group (2-3 days, n = 2586). Clinical outcomes were compared between the groups by propensity matching analysis of 1508 pairs.

RESULTS

There was no significant difference between the early and delayed feeding groups in the rebleeding rate within 7 days after colonoscopy (9.4% vs. 8.0%; p = 0.196) or in the rebleeding rate within 30 days (11.4% vs. 11.5%; p = 0.909). There was also no significant between-group difference in the need for interventional radiology or surgery or in mortality. However, the median length of hospital stay after colonoscopy was significantly shorter in the early feeding group (5 vs. 7 days; p < 0.001). These results were unchanged when subgroups of presumptive and definitive colonic diverticular bleeding were compared.

CONCLUSION

The findings of this nationwide study suggest that early feeding after haemostasis can shorten the hospital stay in patients with ALGIB without increasing the risk of rebleeding.

Weekend Effect on Clinical Outcomes of Acute Lower Gastrointestinal Bleeding: A Large Multicenter Cohort Study in Japan

INTRODUCTION

Weekend admissions showed increased mortality in several medical conditions. This study aimed to examine the weekend effect on acute lower gastrointestinal bleeding (ALGIB) and its mortality and other outcomes.

METHODS

This retrospective cohort study (CODE BLUE-J Study) was conducted at 49 Japanese hospitals between January 2010 and December 2019. In total, 8,120 outpatients with acute hematochezia were enrolled and divided into weekend admissions and weekday admissions groups. Multiple imputation (MI) was used to handle missing values, followed by propensity score matching (PSM) to compare outcomes. The primary outcome was mortality; the secondary outcomes were rebleeding, length of stay (LOS), blood transfusion, thromboembolism, endoscopic treatment, the need for interventional radiology, and the need for surgery. Colonoscopy and computed tomography (CT) management were also evaluated.

RESULTS

Before PSM, there was no significant difference in mortality (1.3% vs. 0.9%, p = 0.133) between weekend and weekday admissions. After PSM with MI, 1,976 cases were matched for each admission. Mortality was not significantly different for weekend admissions compared with weekday admissions (odds ratio [OR] 1.437, 95% confidence interval [CI] 0.785-2.630; p = 0.340). No significant difference was found with other secondary outcomes in weekend admissions except for blood transfusion (OR 1.239, 95% CI 1.084-1.417; p = 0.006). Weekend admission had a negative effect on early colonoscopy (OR 0.536, 95% CI 0.471-0.609; p < 0.001). Meanwhile, urgent CT remained significantly higher in weekend admissions (OR 1.466, 95% CI 1.295-1.660; p < 0.001).

CONCLUSION

Weekend admissions decrease early colonoscopy and increase urgent CT but do not affect mortality or other outcomes except transfusion.

Development and validation of a novel model for predicting stigmata of recent hemorrhage in acute lower gastrointestinal bleeding: Multicenter nationwide study

OBJECTIVES

Stigmata of recent hemorrhage (SRH) directly indicate a need for endoscopic therapy in acute lower gastrointestinal bleeding (LGIB). Colonoscopy would be prioritized for patients with highly suspected SRH, but the predictors of colonic SRH remain unclear. We aimed to construct a predictive model for the efficient detection of SRH using a nationwide cohort.

METHODS

We retrospectively analyzed 8360 patients admitted through hospital emergency departments for acute LGIB in the CODE BLUE-J Study (49 hospitals throughout Japan). All patients underwent inpatient colonoscopy. To develop an SRH predictive model, 4863 patients were analyzed. Baseline characteristics, colonoscopic factors (timing, preparation, and devices), and computed tomography (CT) extravasation were extensively assessed. The performance of the model was externally validated in 3497 patients.

RESULTS

Colonic SRH was detected in 28% of patients. A novel predictive model for detecting SRH (CS-NEED score: ColonoScopic factors, No abdominal pain, Elevated PT-INR, Extravasation on CT, and DOAC use) showed high performance (area under the receiver operating characteristic curve [AUC] 0.74 for derivation and 0.73 for external validation). This score was also highly predictive of active bleeding (AUC 0.73 for derivation and 0.76 for external validation). Patients with low (0-6), intermediate (7-8), and high (9-12) scores in the external validation cohort had SRH identification rates of 20%, 31%, and 64%, respectively (P < 0.001 for trend).

CONCLUSIONS

A novel predictive model for colonic SRH identification (CS-NEED score) can specify colonoscopies likely to achieve endoscopic therapy in acute LGIB. Using the model during initial management would contribute to finding and treating SRH efficiently.

LONG-HOSP Score: A Novel Predictive Score for Length of Hospital Stay in Acute Lower Gastrointestinal Bleeding - A Multicenter Nationwide Study

INTRODUCTION

Length of stay (LOS) in hospital affects cost, patient quality of life, and hospital management; however, existing gastrointestinal bleeding models applicable at hospital admission have not focused on LOS. We aimed to construct a predictive model for LOS in acute lower gastrointestinal bleeding (ALGIB).

METHODS

We retrospectively analyzed the records of 8,547 patients emergently hospitalized for ALGIB at 49 hospitals (the CODE BLUE-J Study). A predictive model for prolonged hospital stay was developed using the baseline characteristics of 7,107 patients and externally validated in 1,440 patients. Furthermore, a multivariate analysis assessed the impact of additional variables during hospitalization on LOS.

RESULTS

Focusing on baseline characteristics, a predictive model for prolonged hospital stay was developed, the LONG-HOSP score, which consisted of low body mass index, laboratory data, old age, nondrinker status, nonsteroidal anti-inflammatory drug use, facility with ≥800 beds, heart rate, oral antithrombotic agent use, symptoms, systolic blood pressure, performance status, and past medical history. The score showed relatively high performance in predicting prolonged hospital stay and high hospitalization costs (area under the curve: 0.70 and 0.73 for derivation, respectively, and 0.66 and 0.71 for external validation, respectively). Next, we focused on in-hospital management. Diagnosis of colitis or colorectal cancer, rebleeding, and the need for blood transfusion, interventional radiology, and surgery prolonged LOS, regardless of the LONG-HOSP score. By contrast, early colonoscopy and endoscopic treatment shortened LOS.

CONCLUSIONS

At hospital admission for ALGIB, our novel predictive model stratified patients by their risk of prolonged hospital stay. During hospitalization, early colonoscopy and endoscopic treatment shortened LOS.

Outcomes and recurrent bleeding risks of detachable snare and band ligation for colonic diverticular bleeding: a multicenter retrospective cohort study

BACKGROUND AND AIMS

Ligation therapy, including endoscopic detachable snare ligation (EDSL) and endoscopic band ligation (EBL), has emerged as an endoscopic treatment for colonic diverticular bleeding (CDB); its comparative effectiveness and risk of recurrent bleeding remain unclear, however. Our goal was to compare the outcomes of EDSL and EBL in treating CDB and identify risk factors for recurrent bleeding after ligation therapy.

METHODS

We reviewed data of 518 patients with CDB who underwent EDSL (n = 77) or EBL (n = 441) in a multicenter cohort study named the Colonic Diverticular Bleeding Leaders Update Evidence From Multicenter Japanese Study (CODE BLUE-J Study). Outcomes were compared by using propensity score matching. Logistic and Cox regression analyses were performed for recurrent bleeding risk, and a competing risk analysis was used to treat death without recurrent bleeding as a competing risk.

RESULTS

No significant differences were found between the 2 groups in terms of initial hemostasis, 30-day recurrent bleeding, interventional radiology or surgery requirements, 30-day mortality, blood transfusion volume, length of hospital stay, and adverse events. Sigmoid colon involvement was an independent risk factor for 30-day recurrent bleeding (odds ratio, 1.87; 95% confidence interval, 1.02-3.40; P = .042). History of acute lower GI bleeding (ALGIB) was a significant long-term recurrent bleeding risk factor on Cox regression analysis. A performance status score of 3/4 and history of ALGIB were long-term recurrent bleeding factors on competing risk regression analysis.

CONCLUSIONS

There were no significant differences in outcomes between EDSL and EBL for CDB. After ligation therapy, careful follow-up is required, especially in the treatment of sigmoid diverticular bleeding during admission. History of ALGIB and performance status at admission are important risk factors for long-term recurrent bleeding after discharge.

Multicenter propensity score-matched analysis comparing short versus long cap-assisted colonoscopy for acute hematochezia

Background and Aim

While short and long attachment caps are available for colonoscopy, it is unclear which type is more appropriate for stigmata of recent hemorrhage (SRH) identification in acute hematochezia. This study aimed to compare the performance of short versus long caps in acute hematochezia diagnoses and outcomes.

Methods

We selected 6460 patients who underwent colonoscopy with attachment caps from 10 342 acute hematochezia cases in the CODE BLUE-J study. We performed propensity score matching (PSM) to balance baseline characteristics between short and long cap users. Then, the proportion of definitive or presumptive bleeding etiologies found on the initial colonoscopy and SRH identification rates were compared. We also evaluated rates of blood transfusions, interventional radiology, or surgery, as well as the rate of rebleeding and mortality within 30 days after the initial colonoscopy.

Results

A total of 3098 patients with acute hematochezia (1549 short cap and 1549 long cap users) were selected for PSM. The rate of colonic diverticular bleeding (CDB) diagnosis was significantly higher in long cap users (P = 0.006). While the two groups had similar rates of the other bleeding etiologies, the frequency of unknown etiologies was significantly lower in long cap users (P < 0.001). The rate of SRH with active bleeding was significantly higher in long cap users (P < 0.001). Other clinical outcomes did not differ significantly.

Conclusion

Compared to that with short caps, long cap-assisted colonoscopy is superior for the diagnosis of acute hematochezia, especially CDB, and the identification of active bleeding.

Differences between patients with inpatient-onset and outpatient-onset acute lower gastrointestinal bleeding: An observational study

BACKGROUND AND AIM

The clinical severity and course of acute lower gastrointestinal bleeding (ALGIB) are believed to differ between inpatient-onset and outpatient-onset cases, but no reports have investigated these issues in detail. We aimed to evaluate the clinical differences between inpatient-onset and outpatient-onset ALGIB.

METHODS

Medical records of patients who had undergone emergency colonoscopy for ALGIB were retrospectively reviewed. The severity was evaluated using the NOBLADS score. Patients with obvious ALGIB relapse and/or persistent iron-deficiency anemia after emergency colonoscopy were considered to exhibit a poor clinical course.

RESULTS

We reviewed 723 patients with ALGIB and divided them into the inpatient-onset cohort (172 patients) and outpatient-onset cohort (551 patients). Compared with the outpatient-onset cohort, the inpatient-onset cohort had a significantly higher proportion of patients with a poor clinical course (51.2% vs 21.6%; P < 0.001) and a significantly higher mean NOBLADS score (3.6 ± 1.1 vs 2.5 ± 1.0; P < 0.001). The most common bleeding source was acute hemorrhagic rectal ulcer (52.3%) in the inpatient-onset cohort and colonic diverticular bleeding (29.4%) in the outpatient-onset cohort. Multivariate analysis showed that a platelet count < 15 × 104 /μL and albumin concentration < 3 g/dL were significantly associated with a poor clinical course in the inpatient-onset cohort.

CONCLUSIONS

The clinical course was significantly worse in the inpatient-onset cohort than in the outpatient-onset cohort. The bleeding source, clinical characteristics, and clinical course differed between the inpatient-onset and outpatient-onset cohorts. The clinical course in the inpatient-onset cohort may depend on the patient's condition at ALGIB onset.

Management of Patients With Acute Lower Gastrointestinal Bleeding: An Updated ACG Guideline

Acute lower gastrointestinal bleeding (LGIB) is a common reason for hospitalization in the United States and is associated with significant utilization of hospital resources, as well as considerable morbidity and mortality. These revised guidelines implement the Grading of Recommendations, Assessment, Development, and Evaluation methodology to propose recommendations for the use of risk stratification tools, thresholds for red blood cell transfusion, reversal agents for patients on anticoagulants, diagnostic testing including colonoscopy and computed tomography angiography (CTA), endoscopic therapeutic options, and management of antithrombotic medications after hospital discharge. Important changes since the previous iteration of this guideline include recommendations for the use of risk stratification tools to identify patients with LGIB at low risk of a hospital-based intervention, the role for reversal agents in patients with life-threatening LGIB on vitamin K antagonists and direct oral anticoagulants, the increasing role for CTA in patients with severe LGIB, and the management of patients who have a positive CTA. We recommend that most patients requiring inpatient colonoscopy undergo a nonurgent colonoscopy because performing an urgent colonoscopy within 24 hours of presentation has not been shown to improve important clinical outcomes such as rebleeding. Finally, we provide updated recommendations regarding resumption of antiplatelet and anticoagulant medications after cessation of LGIB.

Timing of colonoscopy in acute lower GI bleeding: a multicenter retrospective cohort study

BACKGROUND AND AIMS

We aimed to determine the optimal timing of colonoscopy and factors that benefit patients who undergo early colonoscopy for acute lower GI bleeding.

METHODS

We identified 10,342 patients with acute hematochezia (CODE BLUE-J study) admitted to 49 hospitals in Japan. Of these, 6270 patients who underwent a colonoscopy within 120 hours were included in this study. The inverse probability of treatment weighting method was used to adjust for baseline characteristics among early (≤24 hours, n = 4133), elective (24-48 hours, n = 1137), and late (48-120 hours, n = 1000) colonoscopy. The average treatment effect was evaluated for outcomes. The primary outcome was 30-day rebleeding rate.

RESULTS

The early group had a significantly higher rate of stigmata of recent hemorrhage (SRH) identification and a shorter length of stay than the elective and late groups. However, the 30-day rebleeding rate was significantly higher in the early group than in the elective and late groups. Interventional radiology (IVR) or surgery requirement and 30-day mortality did not significantly differ among groups. The interaction with heterogeneity of effects was observed between early and late colonoscopy and shock index (shock index <1, odds ratio [OR], 2.097; shock index ≥1, OR, 1.095; P for interaction = .038) and performance status (0-2, OR, 2.481; ≥3, OR, .458; P for interaction = .022) for 30-day rebleeding. Early colonoscopy had a significantly lower IVR or surgery requirement in the shock index ≥1 cohort (OR, .267; 95% confidence interval, .099-.721) compared with late colonoscopy.

CONCLUSIONS

Early colonoscopy increased the rate of SRH identification and shortened the length of stay but involved an increased risk of rebleeding and did not improve mortality and IVR or surgery requirement. Early colonoscopy particularly benefited patients with a shock index ≥1 or performance status ≥3 at presentation.

Nationwide cohort study identifies clinical outcomes of angioectasia in patients with acute hematochezia

BACKGROUND

While angioectasia is an important cause of acute hematochezia, relevant clinical features remain unclear. This study aims to reveal risk factors, clinical outcomes, and the effectiveness of therapeutic endoscopy for patients with acute hematochezia due to angioectasia.

METHODS

This retrospective cohort study was conducted at 49 Japanese hospitals between January 2010 and December 2019, enrolling patients hospitalized for acute hematochezia (CODE BLUE-J study). Baseline factors and clinical outcomes for angioectasia were analyzed.

RESULTS

Among 10,342 patients with acute hematochezia, 129 patients (1.2%) were diagnosed with angioectasia by colonoscopy. The following factors were significantly associated with angioectasia: chronic kidney disease, liver disease, female, body mass index < 25, and anticoagulant use. Patients with angioectasia were at a significant increased risk of blood transfusions compared to those without angioectasia (odds ratio [OR] 2.61; 95% confidence interval [CI] 1.69-4.02). Among patients with angioectasia, 36 patients (28%) experienced rebleeding during 1-year follow-up. The 1-year cumulative rebleeding rates were 37.0% in the endoscopic clipping group, 14.3% in the coagulation group, and 32.8% in the conservative management group. Compared to conservative management, coagulation therapy significantly reduced rebleeding risk (P = 0.038), while clipping did not (P = 0.81). Multivariate analysis showed coagulation therapy was an independent factor for reducing rebleeding risk (hazard ratio [HR] 0.40; 95% CI 0.16-0.96).

CONCLUSIONS

Our data showed patients with angioectasia had a greater comorbidity burden and needed more blood transfusions in comparison with those without angioectasia. To reduce rebleeding risk, coagulation therapy can be superior for controlling hematochezia secondary to angioectasia.

Effectiveness of early colonoscopy in patients with colonic diverticular hemorrhage: A single-center retrospective cohort study

BACKGROUND

Current guidelines recommend colonoscopy within 24 h for acute lower gastrointestinal bleeding; however, the evidence in support for colonic diverticular hemorrhage (CDH) indications remains insufficient.

AIM

To investigate the effectiveness of early colonoscopy on the length of hospital stay for CDH patients.

METHODS

We conducted a single-center retrospective cohort study. Patients who underwent colonoscopy within 24 h of presentation (early group) were compared with those who underwent colonoscopy beyond 24 h of presentation (elective group). The primary outcome was the length of hospital stay, and secondary outcomes were the identification of stigmata of recent hemorrhage (SRH), rebleeding, red blood cell transfusion more than 4 units, and interventional radiology and abdominal surgery after colonoscopy.

RESULTS

We identified 574 CDH cases. Patients were divided into the early (n = 328) and elective (n = 226) groups. After propensity score matching, 191 pairs were generated. The length of hospital stay did not significantly differ between the two groups (early group vs elective group; median, 7 vs 8 d; P = 0.10). The early group had a significantly high identification of SRH (risk difference, 11.6%; 95%CI: 2.7 to 20.3; P = 0.02). No significant differences were found in the rebleeding (risk difference, 4.7%; 95%CI: -4.1 to 13.5; P = 0.35), red blood cell transfusion more than 4 units (risk difference, 1.6%; 95%CI: -7.5 to 10.6; P = 0.82), and interventional radiology and abdominal surgery rate after colonoscopy (risk difference, 0.5%; 95%CI: -2.2 to 3.2; P = 1.00).

CONCLUSION

Early colonoscopy within 24 h, on arrival for CDH, could not improve the length of hospital stay.

Clinical Characteristics and Outcomes of Hospital-Acquired Lower Gastrointestinal Bleeding: A Single Centre Retrospective Cohort Study

Background Lower gastrointestinal bleeding (LGIB) is common in inpatient and outpatient settings; however, there are limited studies on the clinical characteristics and patient outcomes of those with hospital-acquired LGIB. Methods We performed a retrospective cohort study of patients with hospital-acquired LGIB who underwent colonoscopy during hospitalization between January 2017 and December 2021. We described the clinical characteristics, etiology, and clinical outcomes of patients stratified as those undergoing colonoscopy within 24 hours from haematochezia onset (early colonoscopy group) or after 24 hours from onset (late colonoscopy group). We used multivariable logistic regression to identify factors associated with endoscopic intervention in the early and late colonoscopy groups. Results Of the 272 patients included, the median age was 79 years (interquartile range: 72-85 years), 153 (56%) were bedridden, and 172 (63%) had hypoalbuminemia. The most frequent etiology was rectal ulcer (101 cases, 37%), whereas 7 (2.6%) had diverticular bleeding. The endoscopic intervention was performed on 16.7% and 7.9% of early and late colonoscopy patients. There were more patients with both non-severe and severe rebleeding in the early colonoscopy group (16% and 12%, respectively) than in the late colonoscopy group (11% and 6.5%, respectively). Colonoscopy-on-worktime was the only factor independently associated with a higher occurrence of endoscopic intervention. Conclusions In our sample, very old patients with hospital-acquired LGIB required endoscopy mainly due to rectal ulcers. Further studies will be necessary to investigate the differences between community-acquired LGIB and hospital-acquired LGIB and the optimal timing of colonoscopy for these patients.

Effectiveness of early colonoscopy in patients with colonic diverticular hemorrhage: Nationwide inpatient analysis in Japan

OBJECTIVES

Current guidelines recommend colonoscopy within 24 h for acute lower gastrointestinal bleeding; however, the evidence in support for colonic diverticular hemorrhage (CDH) indications remains insufficient. We use a nationwide database to investigate the effectiveness of early colonoscopy for CDH.

METHODS

We conducted a retrospective cohort study using the Japanese Diagnosis Procedure Combination inpatient database and identified patients who were admitted for CDH from 2010 to 2017. Patients who underwent colonoscopy on the same day of admission (early group) were compared with those who underwent colonoscopy on the next day of admission (elective group). The primary outcome was in-hospital mortality, and secondary outcomes were length of hospital stay, total hospitalization cost, fasting period, and the prevalence of re-colonoscopy, interventional radiology or abdominal surgery. Propensity score matching was used to adjust for confounders.

RESULTS

We identified 74,569 eligible patients. Patients were divided into the early (n = 46,759) and elective (n = 27,810) groups. After propensity score matching, 27,696 pairs were generated. In-hospital mortality did not significantly differ between the two groups (0.49% in the early group vs. 0.41% in the elective group; risk difference 0.08%; 95% confidence interval -0.02 to 0.19; P = 0.14). The early group had a significantly longer length of hospital stay, higher total hospitalization cost, longer fasting period, and higher prevalence of re-colonoscopy and abdominal surgery.

CONCLUSIONS

The effectiveness of early colonoscopy conducted on the same day of admission for CDH could not be confirmed. Early colonoscopy may not result in favorable outcomes in CDH patients.

Nature and Clinical Outcomes of Acute Hemorrhagic Rectal Ulcer

Acute hemorrhagic rectal ulcer (AHRU) is a relatively rare disease that can lead to massive hematochezia. Although AHRU is a potentially life-threatening disease, its characteristics and clinical course are not fully understood. In this study, the clinical features were compared between AHRU and lower gastrointestinal bleeding (LGIB) from other causes (non-AHRU). Then, risk factors for all-cause in-hospital mortality in patients with AHRU were identified. A total of 387 consecutive adult patients with LGIB who were managed at two tertiary academic hospitals in Akita prefecture in Japan were retrospectively enrolled. Subjects were divided into AHRU and non-AHRU groups according to the source of bleeding. Regression analyses were used to investigate significant associations, and the results were expressed as odds ratios (ORs) and 95% confidence intervals (CIs). AHRU was found as the bleeding source in 72 (18.6%) of the patients. In comparison to non-AHRU, having AHRU was significantly associated with in-hospital onset, age > 65 years, and systolic blood pressure < 90 mmHg. The AHRU group had a significantly higher in-hospital mortality rate in comparison to the non-AHRU group (18.0% vs. 8.3, p = 0.02), and hypoalbuminemia (<2.5 g/dL) was significantly associated with in-hospital mortality in the AHRU group (OR, 4.04; 95%CI, 1.11−14.9; p = 0.03). AHRU accounts for a substantial portion (18.6%) of LGIB in our area, where the aging rate is the highest in Japan. Since AHRU is a potentially life-threatening disease that requires urgent identification and management, further studies to identify robust risk factors associated with serious clinical outcomes are required.

Optimal candidates for early colonoscopy in the management of acute lower gastrointestinal bleeding

BACKGROUND AND AIM

Early colonoscopy has not shown any advantages over elective colonoscopy in reducing the risk of early rebleeding (≤ 30 days) after acute lower gastrointestinal bleeding (ALGIB). Considering the heterogeneity among patients with ALGIB, we sought to evaluate appropriate candidates for early colonoscopy.

METHODS

A total of 592 patients with ALGIB were enrolled, and the clinical outcomes of early colonoscopy were investigated. Thereafter, the participants were divided into two groups: the recent bleeding group (n = 445), with hematochezia 0-6 h before hospital arrival, and non-recent bleeding group (n = 147). The clinical outcomes yielded by early colonoscopy were assessed in each group.

RESULTS

The multivariate analysis including the entire population revealed that early colonoscopy (< 24 h) did not reduce the risk of early rebleeding (adjusted odds ratio [AOR], 0.88; 95% confidence interval [CI], 0.55-1.39). However, in the subgroup analysis, early colonoscopy independently reduced the risk of early rebleeding in the recent bleeding group (AOR, 0.56; 95% CI, 0.33-0.94). Moreover, a reduction in the need for radiological or surgical intervention (AOR, 0.34), transfusion (AOR, 0.62), and prolonged hospitalization (AOR, 0.42), as well as improvement in diagnostic yield (AOR, 1.78) and endoscopic treatment rates (AOR, 1.66), were observed. Early colonoscopy did not improve the outcomes of the non-recent bleeding group.

CONCLUSIONS

Early colonoscopy is not required for all patients with ALGIB. However, it may be suitable for those with hematochezia 0-6 h before hospital arrival, as it reduces early rebleeding and improves clinical outcomes.

Treatment strategies for reducing early and late recurrence of colonic diverticular bleeding based on stigmata of recent hemorrhage: a large multicenter study

BACKGROUND AND AIMS

Treatment strategies for colonic diverticular bleeding (CDB) based on stigmata of recent hemorrhage (SRH) remain unstandardized, and no large studies have evaluated their effectiveness. We sought to identify the best strategy among combinations of SRH identification and endoscopic treatment strategies.

METHODS

We retrospectively analyzed 5823 CDB patients who underwent colonoscopy at 49 hospitals throughout Japan (CODE-BLUE J-Study). Three strategies were compared: find SRH (definitive CDB) and treat endoscopically, find SRH (definitive CDB) and treat conservatively, and without finding SRH (presumptive CDB) treat conservatively. In conducting pairwise comparisons of outcomes in these groups, we used propensity score-matching analysis to balance baseline characteristics between the groups being compared.

RESULTS

Both early and late recurrent bleeding rates were significantly lower in patients with definitive CDB treated endoscopically than in those with presumptive CDB treated conservatively (<30 days, 19.6% vs 26.0% [P < .001]; <365 days, 33.7% vs 41.6% [P < .001], respectively). In patients with definitive CDB, the early recurrent bleeding rate was significantly lower in those treated endoscopically than in those treated conservatively (17.4% vs 26.7% [P = .038] for a single test of hypothesis; however, correction for multiple testing of data removed this significance). The late recurrent bleeding rate was also lower, but not significantly, in those treated endoscopically (32.0% vs 36.1%, P = .426). Definitive CDB treated endoscopically showed significantly lower early and late recurrent bleeding rates than when treated conservatively in cases of SRH with active bleeding, nonactive bleeding, and in the right-sided colon but not left-sided colon.

CONCLUSIONS

Treating definitive CDB endoscopically was most effective in reducing recurrent bleeding over the short and long term, compared with not treating definitive CDB or presumptive CDB. Physicians should endeavor to find and treat SRH for suspected CDB.

Utility of red dichromatic imaging for identifying the bleeding point in endoscopic hemostasis of colonic diverticular bleeding

Video 1Endoscopic hemostasis of colonic diverticular bleeding using red dichromatic imaging to identify the bleeding point.

Effectiveness and adverse events of endoscopic clipping versus band ligation for colonic diverticular hemorrhage: a large-scale multicenter cohort study

BACKGROUND : Prior studies have shown the effectiveness of both endoscopic band ligation (EBL) and clipping for colonic diverticular hemorrhage (CDH) but have been small and conducted at single centers. Therefore, we investigated which was the more effective and safe treatment in a multicenter long-term cohort study. METHODS : We reviewed data for 1679 patients with CDH who were treated with EBL (n = 638) or clipping (n = 1041) between January 2010 and December 2019 at 49 hospitals across Japan (CODE BLUE-J study). Logistic regression analysis was used to compare outcomes between the two treatments. RESULTS : In multivariate analysis, EBL was independently associated with reduced risk of early rebleeding (adjusted odds ratio [OR] 0.46; P < 0.001) and late rebleeding (adjusted OR 0.62; P < 0.001) compared with clipping. These significantly lower rebleeding rates with EBL were evident regardless of active bleeding or early colonoscopy. No significant differences were found between the treatments in the rates of initial hemostasis or mortality. Compared with clipping, EBL independently reduced the risk of needing interventional radiology (adjusted OR 0.37; P = 0.006) and prolonged length of hospital stay (adjusted OR 0.35; P < 0.001), but not need for surgery. Diverticulitis developed in one patient (0.16 %) following EBL and two patients (0.19 %) following clipping. Perforation occurred in two patients (0.31 %) following EBL and none following clipping. CONCLUSIONS : Analysis of our large endoscopy dataset suggests that EBL is an effective and safe endoscopic therapy for CDH, offering the advantages of lower early and late rebleeding rates, reduced need for interventional radiology, and shorter length of hospital stay.

Endoscopic direct clipping versus indirect clipping for colonic diverticular bleeding: A large multicenter cohort study

BACKGROUND

Direct and indirect clipping treatments are used worldwide to treat colonic diverticular bleeding (CDB), but their effectiveness has not been examined in multicenter studies with more than 100 cases.

OBJECTIVE

We sought to determine the short- and long-term effectiveness of direct versus indirect clipping for CDB in a nationwide cohort.

METHODS

We studied 1041 patients with CDB who underwent direct clipping (n = 360) or indirect clipping (n = 681) at 49 hospitals across Japan (CODE BLUE-J Study).

RESULTS

Multivariate analysis adjusted for age, sex, and important confounding factors revealed that, compared with indirect clipping, direct clipping was independently associated with reduced risk of early rebleeding (<30 days; adjusted odds ratio [AOR] 0.592, p = 0.002), late rebleeding (<1 year; AOR 0.707, p = 0.018), and blood transfusion requirement (AOR 0.741, p = 0.047). No significant difference in initial hemostasis rates was observed between the two groups. Propensity-score matching to balance baseline characteristics also showed significant reductions in the early and late rebleeding rates with direct clipping. In subgroup analysis, direct clipping was associated with significantly lower rates of early and late rebleeding and blood transfusion need in cases of stigmata of recent hemorrhage with non-active bleeding on colonoscopy, right-sided diverticula, and early colonoscopy, but not with active bleeding on colonoscopy, left-sided diverticula, or elective colonoscopy.

CONCLUSIONS

Our large nationwide study highlights the use of direct clipping for CDB treatment whenever possible. Differences in bleeding pattern and colonic location can also be considered when deciding which clipping options to use.

Outcomes in high and low volume hospitals in patients with acute hematochezia in a cohort study

Outcomes of acute lower gastrointestinal bleeding have not been compared according to hospital capacity. We aimed to perform a propensity score-matched cohort study with path and mediation analyses for acute hematochezia patients. Hospitals were divided into high- versus low-volume hospitals for emergency medical services. Rebleeding and death within 30 days were compared. Computed tomography, early colonoscopy (colonoscopy performed within 24 h), and endoscopic therapies were included as mediators. A total of 2644 matched pairs were yielded. The rebleeding rate within 30 days was not significant between high- and low-volume hospitals (16% vs. 17%, P = 0.44). The mortality rate within 30 days was significantly higher in the high-volume cohort than in the low-volume cohort (1.7% vs. 0.8%, P = 0.003). Treatment at high-volume hospitals was not a significant factor for rebleeding (odds ratio [OR] = 0.91; 95% confidence interval [CI], 0.79-1.06; P = 0.23), but was significant for death within 30 days (OR = 2.03; 95% CI, 1.17-3.52; P = 0.012) on multivariate logistic regression after adjusting for patients' characteristics. Mediation effects were not observed, except for rebleeding within 30 days in high-volume hospitals through early colonoscopy. However, the direct effect of high-volume hospitals on rebleeding was not significant. High-volume hospitals did not improve the outcomes of acute hematochezia patients.