Approximately one in every four patients with ulcerative colitis will develop acute severe ulcerative colitis (ASUC). Historically, this was management with intravenous steroids and surgery when steroids failed. The use of rescue therapy. This review summarizes the latest research in the management of hospitalized patients with ASUC. Covering the historical data and success of rescue therapy with cyclosporine and then with infliximab changed outcomes and reduced the risk of colectomy during the hospitalization and at one year. More recently, more biologics and small molecules have been approved and more patients present to the hospital with ASUC already failing anti-tumor necrosis factor antagonists. More recent studies have shown some efficacy of rescue therapy with other classes of biologics (e.g. interleukins and anti-integrins). The more recently approved small molecules (i.e. tofacitinib and Upadacitinib) have shown a rapid onset in therapeutic efficacy in as little as one day with sustained response at one year in reducing the risk of colectomy following ASUC. In the expert opinion, we discuss the challenges in the treatment of patients with ASUC. We summarize the data of current biologics and new small molecules and their emerging roles in the management of ASUC.