Following extensive abdominal surgery for the treatment of endometrial or ovarian cancer, paralytic ileus frequently develops. Gum chewing can promotes the return of bowel function through the cephalic-vagal reflex and increased intestinal enzymes secretion.

The objectives of this study are to evaluate effects of adding gum chewing to the conventional postoperative feeding protocol on the return of bowel function, its related complications, and patients' satisfaction.

Inclusion Criteria:

• Patients undergoing staging or cytoreductive surgery for primary endometrial or ovarian cancer at Maharaj Nakorn Chiang Mai hospital

Exclusion Criteria:

• Perioperative hyperalimentation
• Recent chemotherapy (within 3 weeks before surgery)
• Previous bowel surgery
• Inflammatory bowel diseases
• Previous abdominal or pelvic radiation
• Need for immediate postoperative endotracheal intubation
• Need for postoperative admission to intensive care unit
• Undergoing emergency surgery with oral intake of fluid or food within 4 hours before surgery