ObjectiveTo compare the postoperative nausea and vomiting (PONV) after laparoscopic sleeve gastrectomy (LSG) and single-anastomosis sleeve ileal bypass (SASI), and to explore the risk factors for PONV. MethodA total of 220 patients at the Affiliated Hospital of Xuzhou Medical University from June 2022 to December 2022 were prospectively collected, and were randomly divided into the LSG group and the SASI group; the general condition of the patients was recorded. PONV was assessed on the POD0, POD1, POD2, POD30, POD60, POD90, using the Rhodes index score.ResultsThe total Rhodes index score in the LSG group was higher than that in the SASI group [(25.56±13.54) vs. (16.06±11.28), P＜0.05]. The results of multiple linear regression analysis showed that female (P=0.014), LSG (P＜0.001), young age (P=0.050), and low BMI (P=0.019) were risk factors for PONV. ConclusionsCompared with LSG, the Rhodes index score after SASI is low. For young women with low BMI, special attention should be paid to the prevention and treatment of PONV after LSG.