Ulcerative colitis (UC) is a chronic inflammatory disease of the colon and rectum. Surgery for UC is indicated in five instances: 1. Acute colitis unresponsive to medical therapy; 2. disease which is later refractory to medical treatment; 3. patients who fail to tolerate medical treatment or its adverse effects, including steroid-dependent disease; 4. cases of neoplastic or dysplastic transformation of the intestinal mucosa; 5. and in the pediatric setting where there is failure to thrive.

Two decades ago, data from a population-based follow-up from Sweden estimated that 25–30 % of patients with UC require colectomy over the course of their lifetime [1] However, the advent of biologic therapy which is probably the most relevant advancement in the treatment of patients with inflammatory bowel disease (IBD) in the last two decades, have reduced the rate of elective colectomies and modify the timing and the type of the surgical approach. Several studies currently available in the international literature, in fact, have demonstrated a lower rate of elective colectomies in ulcerative colitis. In the past two decades. Kroner et al. in a review of the National Inpatient sample from 2009 to 2018 reported an increase of hospitalization for UC, but a decrease in the rate of surgery [2] In a recent paper, Olivera et al. reviewing population-based data from cohort from referral centers, demonstrated a significant reduction of colectomy in UC for refractory disease in patients treated with biologics [3] Recent population-based cohort study from Switzerland observed 5-, 10-, 15-, and 20-year cumulative colectomy rates after diagnosis of 4.1 %, 6.4 %, 10.4 %, and 14.4 %, respectively [4] A reduction of elective colectomy rates was also reported by Koltze in the Canadian population after the approval of Infliximab [5]. A trend toward a reduction of elective colectomies was also reported in the UK [6]. The possible explanation of this phenomenon is that growing armamentarium of biologics now available gives patients the opportunity to experiment different medical treatment, to achieve durable steroid-free remission in a considerable percentages of patients and ultimately to delay the date of surgery The main consequence is that when patients need surgery, they often come in a malnourished and catabolic state, with exhausted physiological reserve, often suffering from disease or therapy related complications as a result of the exposure to different class of biologic, which potentially could increase the rate of postoperative complications. This latter issue, however, is still a matter of controversy and debate and no definitive conclusions could be drawn due to contrasting results reported by large reviews and meta-analysis [[7], [8], [9], [10], [11]]. Despite a lack of evidence and inconclusive results, nevertheless, surgeons feared to the possible increase of surgical complications have modified their surgical strategy increasing the staged nature of the surgical intervention [12]. The standard surgical procedure adopted in the management of patents with UC is represented by proctocolectomy with ileal pouch-anal anastomosis (IPAA) without defunctioning ileostomy (single stage), or with protective ileostomy which will be reversed at a later time (conventional two stage). This option should be reserved to ideal candidate I.e., patients in good nutritional status, with no severe comorbidities and not taking steroids. The other options include “modified” two-stage (colectomy, followed by later completion proctectomy and IPAA without diversion), and lastly three-stage (colectomy, completion proctectomy with IPAA and diversion, and stoma reversal). This latest option is preferred in high-risk patients, allows for improved patient recovery between operations, thereby reducing the risk of complications associated with more extensive single-stage procedure [13]. In recent years, according to the aforementioned considerations an increase adoption of a three stage procedure has been reported. Abelson reported between 2005 and 2013 an increased number of patients doing at least three procedures from 9 to 14 % [11]. Advancing medical therapy and biologic should not be considered the solely responsible of the change in the surgical approach to medical-refractory UC. The chance to perform even in an urgent setting a total colectomy using a mini-invasive approach, with low rate of postoperative complications, lower length of hospital stay, reduced postoperative adhesions have also influence surgeon's strategy and currently laparoscopic subtotal colectomy with ileostomy is the recommended approach for immunosuppressed patients with moderate to severe colitis [14,15].

Aim of the present paper is to analyze the main changes in pouch surgery with respect to staged approach, role of minimally invasive approach and trans-anal approach.