Background: Acute severe ulcerative colitis (ASUC) affects up to 25% of patients with UC and is associated with an increased risk of colectomy. Despite improvements in medical management, individual patient prognostication and risk stratification in ASUC remains challenging. We explored clinical, biochemical, and endoscopic factors as potential predictors for colectomy in patients hospitalized with ASUC.

Methods: A retrospective analysis of patients with ASUC as defined by Truelove and Witts criteria admitted to the Mount Sinai Hospital between 2011 and 2020 was conducted. Data on disease history, medication use, clinical symptoms, and laboratory results during admission for ASUC were included. Colectomy risk during hospitalization and within one year was assessed.

Results: We included 158 patients; 34 (21.5%) underwent colectomy during hospital admission and 41 (25.9%) within a year. On multivariable analysis, prior anti-TNF exposure (odds ratio [OR] 4.59, 95% confidence interval [CI] 1.57-13.4, P = 0.005), and biologic use at admission (OR 3.31, 95%CI 1.14-9.63, P = 0.028) were associated with an increased risk of 1-year colectomy. Conversely, mesalamine use at admission decreased this risk (OR 0.31, 95%CI 0.13-0.72, P = 0.006). Other risk factors included recent UC-related hospitalization (< 1 year of admission), higher bowel movement frequency after 3 days of treatment, low hemoglobin and albumin levels, and elevated CRP. Infliximab treatment was associated with decreased risk of urgent (OR 0.30, 95%CI 0.13-0.73, P = 0.007) and 1-year colectomy (OR 0.31, 95%CI 0.14-0.73, P = 0.007).

Conclusions: In patients with ASUC, prior anti-TNF exposure is linked to a higher risk of both short- and long-term colectomy, while recycling infliximab may reduce colectomy risk.