1 g nil per os postoperatively until return of bowel sounds.

2 olume of gastric aspirate or the presence of bowel sounds.

3 presence of abdominal distension, absence of bowel sounds, and positive end-expiratory pressure great

4 upper quadrant and lower abdomen and reduced bowel sounds at auscultation.

5 lume of gastric aspirate and the presence of bowel sounds do not correlate with gastric emptying.