The diarrhea sometimes associated with nasogastric tube feeding has been attributed to the cool temperature of the formula. To test the effect of temperature variations of liquid feedings on gastric motility, a strain gauge and feeding tube were surgically implanted in the stomachs of rhesus monkeys. With the monkeys awake and restrained, the investigators infused constant volume of water and liquid diet formula at varying temperatures and recorded gastric motility. The temperature of the liquid did not significantly alter gastric motility or gastric emptying, suggesting that the temperature of administration of the tube feeding is not a cause of diarrhea.