Sigmoid volvulus (SV), the wrapping of the sigmoid colon around itself, is a rare colonic obstruction form. SV requires emergency endoscopic or surgical treatment following an urgent resuscitation and the prognosis is relatively poor. Although many different classifications have been made for SV in the past, the unique classification system, which assists the decision making in the management in addition to the estimation of the prognosis, was described in 2017. Thereafter, a great number of relevant subjects were discussed in the literature. The aim of this study is to update the present classification system in light of abovementioned discussions and our experience with 1,028 SV patients, which is the largest single-centre SV series over the world.