Chapter 297 Normal Digestive Tract Phenomena
Gastrointestinal function varies with maturity; what is a physiologic event in a newborn or infant might be a pathologic symptom at an older age. A fetus can swallow amniotic fluid as early as 12 wk of gestation, but nutritive sucking in neonates 1st develops at about 34 wk of gestation. The coordinated oral and pharyngeal movements necessary for swallowing solids develop within the 1st few months of life. Before this time, the tongue thrust is upward and outward to express milk from the nipple, instead of a backward motion, which propels solids toward the esophageal inlet. By 1 mo of age, infants appear to show preferences for sweet and salty foods. Infants’ interest in solids increases at about 4 mo of age. The recommendation to begin solids at 6 mo of age is based on nutritional and cultural concepts rather than maturation of the swallowing process (Chapter 42). Infants swallow air during feeding, and burping is encouraged to prevent gaseous distention of the stomach.
