A case of pneumatosis intestinalis was associated with milk intolerance in a preterm newborn infant. The infant's clinical condition and bloody diarrhea improved on a milk-free diet. The symptoms recurred when the infant was challenged with milk. The milk intolerance, starting at the age of 20 hours, was thought to be secondary to transient lactose intolerance which has been reported in premature infants.
Management included a short period of total parenteral feeding followed by a milk-free diet. There was complete recovery. A lactose tolerance test at age 9 months was normal after which the infant tolerated milk without any complications. Results of follow-up of the infant showed normal growth and development.