Time of the first defaecation and urination in very low birth weight infants.

The time for passage of the first stool and urine was studied in 111 infants who weighed less than 1500 g at birth. Delayed passage of the first stool (greater than 24 h) was noted in 25 (22.5%) infants of this group, including 7 cases (6.3%) in whom the delay was greater than 48 h (4 on the 3rd day, 2 on the 4th day, 1 on the 6th day of life, respectively). Three (2.7%) cases had delayed passage of the first urine (at 25, 25, and 45 h of life, respectively). Significant differences between the two groups with delayed and nondelayed passage of the first stool were noted in both the gestational age and in the time of the first enteral feeding. In very low birth weight infants, delay in the passage of the first stool is a common occurrence. This delay is probably due to physiological immaturity of the motor mechanisms of the gut, and lack of triggering effect of enteral feeds on gut hormones. As far as passage of the first urine was concerned, there were no significant perinatal factors found between the delayed and nondelayed groups.