Infants typically urinate 15 to 20 times per day. The urine varies in color from nearly clear to dark yellow. Stools vary a great deal among infants in frequency, color, and consistency depending on the nature of the individual infants and the contents of their diet. The number of times infants defecate varies from once every other day to 6 or 8 times a day. Stool consistency ranges from firm and formed to soft and runny. Stool color ranges from mustard yellow to dark brown. The stool of breastfed infants tends to be softer and of lighter color than that of formula-fed infants.
Diapers must be changed often to keep the underlying skin dry. Wet skin chafes more easily than dry skin and is more likely to develop diaper rash. Modern, super-absorbent disposable diapers contain a layer of gel that absorbs liquid and keeps it away from the skin. These diapers keep skin drier than cloth diapers after small to moderate amounts of urine, but diapers of any type should be changed when the skin is exposed to wetness. Bacteria normally present in stool can break down urea, a substance in urine, resulting in an alkaline pH that irritates the skin, so diapers should be checked frequently for stool and changed immediately.
Baby powders help keep skin dry when the infant is sweating slightly, but they do not help keep the skin dry from urine or stool and are not essential. Powder made of talcum may cause lung problems if inhaled by infants, so parents should purchase baby powders that contain cornstarch instead.