Impact of Cardiopulmonary Bypass Time on Gastrointestinal Complications

Inclusion Criteria: * Patients undergoing heart valve replacement with CPB * Age ≥ 18 years and ≤ 75 years Exclusion Criteria: * Have received major gastrointestinal surgery within 5 years. * History of severe infection (e.g., pneumonia, urinary tract infection) requiring hospitalization within 1 month prior to surgery. * Inflammatory bowel disease (IBD), including ulcerative colitis, Crohn's disease, or colitis. * Acute gastroenteritis. * Clostridium difficile or Helicobacter pylori infection. * Chronic constipation. * Peptic ulcer. * Polyps in the stomach or intestines. * Gastrointestinal neoplasms. * Abdominal hernia. * Irritable bowel syndrome. * Acute or chronic cholecystitis, hepatitis. * Patients who died intraoperatively or within 24 hours postoperatively. * Patients with digestive system tumors. * Pregnancy or breastfeeding could affect postoperative medication use and study observations. * Involvement in other studies that may interfere with the objective results of this study.