Effects of dexmedetomidine combined with transversus abdominis plane block on postoperative gastrointestinal function in patients undergoing laparoscopic colorectal surgery

Intervention group:Dexmedetomidine is pumped before the anesthesia induction and during the operation;Bilateral transversus abdominis plane block is performed before the anesthesia induction;Control group:The same dose of normal saline is pumped before the anesthesia induction and during the operation Primary outcome(s): Incidence of POGD Study Design: Parallel