Risk factors and outcome of acute severe lower gastrointestinal bleeding in Crohn's disease.

Background: Acute severe lower gastrointestinal bleeding in Crohn's disease is uncommon, but is a diagnostic and therapeutic challenge. We aimed to identify risk factors for acute lower gastrointestinal bleeding in patients with Crohn's disease and assess the cumulative probability of rebleeding in relation to therapeutic modality.

Methods: We retrospectively reviewed the medical records of 70 Crohn's patients (4.