Abstract Background The effect of a combination of a goal-directed fluid protocol and preoperative carbohydrate loading on postoperative complications in elderly patients still remains unknown. Therefore, we designed this trial to evaluate the relative impact of preoperative carbohydrate loading and intraoperative goal-directed fluid therapy versus conventional fluid therapy (CFT) on clinical outcomes in elderly patients following gastrointestinal surgery. Methods This prospective randomized controlled trial with 120 patients over 65 years undergoing gastrointestinal surgery were randomized into a CFT group (n = 60) with traditional methods of fasting and water-deprivation, and a GDFT group (n = 60) with carbohydrate (200 ml) loading 2 h before surgery. The CFT group underwent routine monitoring during surgery, however, the GDFT group was conducted by a Vigileo/FloTrac monitor with cardiac index (CI), stroke volume variation (SVV), and mean arterial pressure (MAP). For all patients, demographic data, intraoperative parameters and postoperative outcomes were recorded. Results Patients in the GDFT group received significantly less crystalloids fluid (1111 ± 442.9 ml vs 1411 ± 412.6 ml; p 0.05). Conclusions Focused on elderly patients undergoing open gastrointestinal surgery, we found perioperative fluid optimisation may be associated with improvement of bowel function and a lower incidence of postoperative complications. Trial registration ChiCTR, ChiCTR1800018227 . Registered 6 September 2018 - Retrospectively registered.