Milk bolus obstruction of the neonatal bowel apparently related to the use of artificial powder milk, particularly full cream cows milk, was first recognised in the late 1960s. The syndrome almost disappeared with the use of highly modified cows milk formulae but has now re-emerged in the low birth weight population with the early use of high calorific feeds specifically designed for these infants. We describe four cases of obstruction and perforation of the bowel seen on our neonatal intensive care unit in 1 calendar year and discuss the possible aetiology of this condition.