Background:The long-term outcome of patients with acute severe ulcerative colitis (ASUC) responding to intravenous steroids (IVS) has been poorly reported. Aims:To assess relapse-free survival in patients with ASUC responding to IVS. Methods:Between January 2006 and December 2017, 142 consecutive patients with ASUC (according to modified Truelove-and-Witts criteria) responding to IVS were included in this multicentre retrospective study. Relapse was defined by a partial Mayo Clinic score >4 and/or the need for another maintenance therapy.Results: Among the 142 included patients (100 naïve of immunomodulator and/or biological agent) hospitalised for ASUC, 59 (41.5%) were treated at discharge with 5-aminosalicylic acid, 60 (42%) with immunomodulators, 18 (13%) with anti-tumour necrosis factor (TNF) agents and 5 (3.5%) with vedolizumab. After a median followup of 4.8 (2.6-7.3) years, 90 (63.4%) had relapsed and 12 (8.5%) had required colectomy. The probabilities of relapse-free survival were 58%, 48% and 40% at 1, 2 and 5 years respectively. The multivariate analysis demonstrated that patients with <6 liquid stools per day at day 3 (hazard ratio 0.56, 95%CI [0.34-0.91]), a partial Mayo Clinic score <2 at day 5 (0.41 [0.21-0.80]) and anti-TNF maintenance therapy (0.37 [0.16-0.87]) were less likely to relapse. The probabilities of colectomy-free survival were 96%, 95% and 91% at 1, 2 and 5 years respectively. Conclusion:Despite a high relapse rate, patients with ASUC responding to IVS had a low rate of colectomy after 5 years of follow-up. Early response to IVS and maintenance therapy with biological agents were associated with a lower rate of relapse. | INTRODUC TI ONUlcerative colitis (UC) is a chronic and disabling disease characterised by a sequence of flares and remission. 1 In up to 25% of cases, patients with UC will develop a severe exacerbation of the disease and require hospitalisation and intravenous steroids (IVS). 2 Acute severe ulcerative colitis (ASUC) is a life-threatening condition with an estimated risk of mortality of 1%-2% and emergency colectomy of 30%. 3,4 Management of ASUC relies on a multidisciplinary approach with gastroenterologists and surgeons and requires hospitalisation for intensive medical therapy. 5 IVS therapy remains the mainstream treatment for patients with ASUC together with fluid and electrolyte resuscitation, nutritional support and thromboprophylaxis. 6Since the 1970s, the effectiveness of this intensive medical therapy has not changed over time, with an overall response rate of 67%. 4

LINKED CONTENTThis article is linked to Salameh et al and Fábián et al papers. To view these articles, visit https://doi.org/10.1111/apt.15751 and https://doi.org/10.1111/apt.15968