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. [ABSTRACT FROM AUTHOR]