We examine the indications and the operative options for proceeding to emergency surgery in patients with inflammatory bowel disease. Emergency surgery is absolutely mandatory in case of generalized peritonitis due to bowel perforation. Other life-treating complications are acute disease not responding to medical treatment, toxic megacolon, bowel obstruction and massive hemorrhage. Early medical treatment of these conditions often prevents most severe clinical expressions and improves the prognosis. However surgery should be performed immediately if there is no improvement within 5 days of medical management in case of acute colitis, within 24-48 hours in case of toxic megacolon, within 48-72 hours in patients with intestinal obstruction or severe bleeding, or if the patient deteriorates during this period. In such circumstances, subtotal colectomy with ileostomy and mucous fistula of distal sigmoid colon is the best procedure. That is because it is relatively easy to perform and consents a simpler restorative operation than other procedures preserving the rectum. Moreover it leads to lower morbidity and mortality than the total proctocolectomy that should be reserved to patients with severe rectal disease or sphincter lesion. The most important factors influencing outcome of complicated or severe inflammatory bowel disease are the choice of the appropriate timing for surgery and the procedure performed.