['This study determined the long-term outcome after colectomy for acute severe ulcerative colitis (ASUC) and assessed whether the duration of in-hospital medical therapy is related to postoperative outcome.', 'All patients who underwent urgent colectomy and ileostomy for ASUC between 1994 and 2000 were identified from a prospective database. Patient details, preoperative therapy and complications to last follow-up were recorded.', 'Eighty patients were identified, who were treated with intravenous steroids for a median of 6 (range 1-22) days before surgery. Twenty-three (29 per cent) also received intravenous ciclosporin. There were 23 complications in 22 patients in the initial postoperative period. Sixty-eight patients underwent further planned surgery, including restorative ileal pouch-anal anastomosis in 57. During a median follow-up of 5.4 (range 0.5-9.0) years, 48 patients (60 per cent) developed at least one complication. Patients with a major complication at any time during follow-up had a significantly longer duration of medical therapy before colectomy than patients with no major complications (median 8 versus 5 days; P = 0.036).'] Is delayed surgery for acute severe colitis associated with increased risk of postoperative complications?