Validation of British Society of Gastroenterology guidelines for acute lower gastrointestinal bleeding from 8,956 cases in Japan.

Background and aims: We sought to validate the British Society of Gastroenterology (BSG) guidelines for acute lower gastrointestinal bleeding (ALGIB).

Methods: We analyzed 8,956 patients with ALGIB in CODE BLUE-J study and categorized them into four groups based on BSG guidelines. Outcomes included 30-day rebleeding, 30-day mortality, blood transfusion, therapeutic intervention, and severe bleeding.

Results: The severe bleeding rates significantly decreased from Group I to IV: 92.1%, 70.1%, 58.7%, and 38.4%. The rate of the need for blood transfusion and 30-day mortality also decreased from I to IV. Although outpatient follow-up was recommended in Group IV, it had high rates of severe bleeding (38%) and 30-day rebleeding (11%). Notably, for colonic diverticular bleeding, the rate of 30-day rebleeding was 25.5%, even with an Oakland score ≤ 8. We identified abdominal pain, diarrhea, and a high white blood cell count as independent factors that differentiate between non-severe and severe bleeding cases in Group IV. Using these factors, the 30-day rebleeding rate in the non-severe group was 3.6%, suggesting the feasibility of outpatient follow-up in this group. Furthermore, a novel, Group X, which deviated from the existing four groups, had a high severe bleeding rate (70.9%) comparable to that of Group II.

Conclusions: The BSG guidelines suggest a management approach that can clearly differentiate severity. However, caution is advised when using the Oakland score to triage patients for outpatient follow-up. Additionally, prompt intervention may be necessary for groups not covered by the guidelines.