The policies which exist to monitor the passage of neonatal stool vary between and within hospitals. When stool colour is required, the recorded observations are invariably subjective opinions and as such are largely unreliable. The development of a stool colour comparator allowed an objective test to be used by professional staff and mothers. This facilitated data collection for a study which sought to determine, among other factors, the transition time of meconium through to the yellow stool of the milk-fed baby, during the early neonatal period. The transition time of the meconium is indicative of gastrointestinal activity in the newborn and midwives are able to correlate accurately documented changes in stool colour with the baby's daily weight loss to assess the quality and/or adequacy of early infant feeding particularly breast feeding. The stool colour comparator is used in postnatal wards at Ninewells Hospital, Dundee by mothers and midwives and the numerical coding has replaced the previously used subjective abbreviations Mec (Meconium), Ch (Changing) and Y (Yellow).