INTRODUCTION The bleeding source of hematochezia is unknown without performing colonoscopy. We sought to identify whether colonoscopy is a risk-stratifying tool to identify etiology and predict outcomes and whether presenting symptoms can differentiate the etiologies in patients with hematochezia. METHODS This multicenter retrospective cohort study conducted at 49 hospitals across Japan analyzed 10,342 patients admitted for outpatient-onset acute hematochezia. RESULTS Patients were mostly elderly population, and 29.5% had hemodynamic instability. Computed tomography was performed in 69.1% and colonoscopy in 87.7%. Diagnostic yield of colonoscopy reached 94.9%, most frequently diverticular bleeding. Thirty-day rebleeding rates were significantly higher with diverticulosis and small bowel bleeding than with other etiologies. In-hospital mortality was significantly higher with angioectasia, malignancy, rectal ulcer, and upper gastrointestinal bleeding. Colonoscopic treatment rates were significantly higher with diverticulosis, radiation colitis, angioectasia, rectal ulcer, and postendoscopy bleeding. More interventional radiology procedures were needed for diverticulosis and small bowel bleeding. Etiologies with favorable outcomes and low procedure rates were ischemic colitis and infectious colitis. Higher rates of painless hematochezia at presentation were significantly associated with multiple diseases, such as rectal ulcer, hemorrhoids, angioectasia, radiation colitis, and diverticulosis. The same was true in cases of hematochezia with diarrhea, fever, and hemodynamic instability. DISCUSSION This nationwide data set of acute hematochezia highlights the importance of colonoscopy in accurately detecting bleeding etiologies that stratify patients at high or low risk of adverse outcomes and those who will likely require more procedures. Predicting different bleeding etiologies based on initial presentation would be challenging.

中文翻译：

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通过内窥镜检查确定出血病因影响 10,342 例便血病例的结果：CODE BLUE-J 研究。

引言 如果不进行结肠镜检查，便血的出血来源是未知的。我们试图确定结肠镜检查是否是确定病因和预测结果的风险分层工具，以及表现症状是否可以区分便血患者的病因。方法 这项在日本 49 家医院进行的多中心回顾性队列研究分析了 10,342 名因门诊急性便血入院的患者。结果患者以老年人群为主，血流动力学不稳定者占29.5%。69.1% 的患者进行了计算机断层扫描，87.7% 的患者进行了结肠镜检查。结肠镜检查诊断率达94.9%，最常见的是憩室出血。憩室病和小肠出血的三十天再出血率明显高于其他病因。血管扩张、恶性肿瘤、直肠溃疡和上消化道出血的院内死亡率显着较高。憩室病、放射性结肠炎、血管扩张、直肠溃疡和内镜检查后出血的结肠镜治疗率显着较高。憩室病和小肠出血需要更多的介入放射学手术。具有良好结果和低手术率的病因是缺血性结肠炎和感染性结肠炎。就诊时无痛便血的较高发生率与多种疾病显着相关，例如直肠溃疡、痔疮、血管扩张、放射性结肠炎和憩室病。对于伴有腹泻、发热和血流动力学不稳定的便血病例也是如此。讨论 这个全国性的急性便血数据集强调了结肠镜检查在准确检测出血病因方面的重要性，对不良结果高风险或低风险的患者以及可能需要更多手术的患者进行分层。根据最初的表现来预测不同的出血病因将具有挑战性。