This document proposes a classification system for peristomal skin disorders developed through a multicenter observational study across eight ostomy centers in Italy. The study involved 380 patients within one year of surgery and 276 patients more than one year post-surgery. The classification system identifies five lesion types (L1-L4, LX) and their location based on quadrants around the stoma. The study aims to provide an objective and reproducible tool to classify peristomal skin disorders and improve ostomy patient quality of life.