There are many causes of constipation in newborns, including feeding practices, bowel dysfunction, disease and medication. If a newborn does not pass faeces within 24 hours of birth, the doctor will consider delayed faecal excretion and the presence of certain conditions that cause constipation, such as abnormalities of the digestive tract, metabolic disorders, neuroendocrine disorders and poisoning. In addition, certain medications can also cause constipation in newborns, such as opiates and phenobarbital.