INTRODUCTION: Patients with cirrhosis have increased portal-systemic shunting and intestinal permeability, and therefore are at risk of bacterial translocation and infectious complications following acute diverticulitis. In this study, we evaluate the effect of cirrhosis on the outcomes of hospitalized patients with acute diverticulitis. METHODS: Patient cases with inpatient stays for acute diverticulitis were selected from the 2011 to 2017 National Inpatient Sample and were stratified by the presence of cirrhosis. Patients with coexisting inflammatory bowel disease were excluded from the selection process. The endpoints included mortality, length of stay (LOS), hospitalization costs, and colonic complications. RESULTS: A total of 416573 patients with acute diverticulitis were identified from the database. Of these patients, 3887 (0.93%) had cirrhosis. Compared to the non-cirrhosis cohort, the cirrhosis cohort had no difference in age (63.3 vs 62.8y P = 0.43) but was more likely to be male (54.8 vs 41.7% P < 0.01). The mortality rate was higher in the cirrhosis cohort (4.53 vs 1.32% P < 0.01, OR 3.56 95% CI 3.05–4.15), as were the LOS (7.01 vs 5.40d P < 0.01) and hospitalization costs ($67,048 vs $47,726 P < 0.01). In terms of colonic complications, the cirrhosis cohort had higher incidences of clostridium difficile infection (2.19 vs 0.93% P < 0.01, OR 2.38 95% CI 1.92–2.96), intestinal abscess formation (45.5 vs 43.8% P = 0.04, OR 1.07 95% CI 1.01–1.14), sepsis (16.5 vs 9.19% P < 0.01, OR 1.95 95% CI 1.79–2.12), intestinal fistula (5.15 vs 4.32% P = 0.01, OR 1.20 95% CI 1.04–1.39). However, no difference was found in the incidences of intestinal obstruction (3.83 vs 4.08% P = 0.46, OR 0.94 95% CI 0.79–1.10), volvulus (0.10 vs 0.08% P = 0.84, OR 1.27 95% CI 0.47–3.41), intussusception (0.05 vs 0.04% P = 0.93, OR 1.44 95% CI 0.36–5.79), and fecal impaction (0.36 vs 0.40% P = 0.79, OR 0.90 95% CI 0.53–1.52). The incidence of intestinal perforation was also lower in the cirrhosis cohort (9.31 vs 12.0% P < 0.01, OR 0.75 95% CI 0.67–0.84). In a multivariate model, cirrhosis was found to be associated with increased mortality in patients with acute diverticulitis (P = 0.01, aOR 1.35 95% CI 1.06–1.71). CONCLUSION: Cirrhosis is associated with increased risks of death, infection, and fistulous complications in hospitalized patients with acute diverticulitis. These patients therefore require early risk-assessment and multidisciplinary management of infection and fistulous complications that are detected on imaging or colonoscopy.Figure 1.: Multivariate model: cirrhosis is associated with increased mortality in hospitalized patients with acute diverticulitis.