S Biondo1,2, L Trenti3,4, E Kreisler3,4, C Ratto5. 1. Colorectal Unit, Department of General and Digestive Surgery, Bellvitge University Hospital, University of Barcelona, C/Feixa Llarga s/n, L'Hospitalet de Llobregat, 08907, Barcelona, Spain. sbn.biondo@gmail.com. 2. IDIBELL (Bellvitge Biomedical Investigation Institute), Barcelona, Spain. sbn.biondo@gmail.com. 3. Colorectal Unit, Department of General and Digestive Surgery, Bellvitge University Hospital, University of Barcelona, C/Feixa Llarga s/n, L'Hospitalet de Llobregat, 08907, Barcelona, Spain. 4. IDIBELL (Bellvitge Biomedical Investigation Institute), Barcelona, Spain. 5. Proctology Unit, Department of Surgical Sciences, Catholic University, Rome, Italy.