Lately, emerging data suggest an association between the development of inflammatory bowel disease and anti-interleukin-17 therapy. Megacolon is a life-threatening complication of acute severe ulcerative colitis (ASUC), but its treatment has not yet been established in current practice guidelines. We report a rare case of known psoriasis treated by secukinumab in a patient who presented with ASUC and colonic dilatation. Neither steroids nor standard infliximab regimen was effective. Finally, rescue therapy with accelerated infliximab strategy resulted in excellent recovery. In certain cases of steroid-refractory ASUC complicated by megacolon, accelerated infliximab regimen can be an alternative to surgery.