University Hospital Southampton NHS Foundation Trust

Meconium Plug

Term babies should pass meconium (baby poo) in the first 24 hours following delivery. This normally means a messy nappy!

A meconium plug is poo enclosed in a mucus coat which is often more difficult for your baby to pass. Some babies may pass just one plug, others pass more. Your baby may pass this plug:

  • spontaneously
  • following an examination of its bottom
  • as the result of a rectal washout
  • following an x-ray investigation

In most babies who pass plugs no cause is found. However in some babies we know there may be an underlying reason. Babies who pass meconium plugs are thought to have an increased risk of either Cystic Fibrosis or Hirschsprung's disease. There is a simple test we can do to exclude each of these conditions.

We can test your baby for Cystic Fibrosis by taking a blood sample and we can test for Hirschsprung's Disease by taking a sample of tissue from the lining of the rectum with a small instrument through your baby's bottom. This is called a Rectal Suction Biopsy.

What happens while we wait for the results of these tests?

Both these tests take approximately five working days to obtain the results.

Following the passage of a meconium plug you baby may behave and feed entirely normally. However your baby may have a swollen tummy because of a build up of meconium, wind and milk in the bowel. This may also cause them to be sick. The vomit will often be green due to the presence of bile.

If this happens a drip will be placed into a small vein so that intravenous fluids can be given, as your baby will not be able to feed in the normal way. A tube will be passed through your baby’s nose into the stomach to drain away the bile (green fluid) that collects here. This lessens the risk of vomiting and reduces discomfort. When the bowel is emptied your baby can resume normal milk feeds.

Because babies with Hirschsprung's Disease can develop a serious infection of the bowel, we will arrange for your baby to have washouts of their bowel at least once a day until the results are known. This normally means your baby staying in hospital but sometimes it may be possible to arrange this at either your local hospital or at home by a community nurse.


In most cases the results will be negative and your baby will be able to go home once the results are confirmed. Passing meconium plugs does not appear to affect these babies in later life.

If, however, your baby has a positive result for either of these conditions, they will then be referred to the relevant specialist who will explain in detail the care and management your baby may require. If you prefer we can give you further information whilst awaiting the results.

We appreciate that this will be a worrying time for you and your family so please speak to either a nurse or doctor looking after your baby if you have any further questions or contact us.


University Hospital Southampton NHS Foundation Trust produce guidelines as an aid to good clinical practice. They represent recognised methods and techniques of clinical practice, based on published evidence. The ultimate judgement regarding a particular clinical procedure or treatment must be made by the clinician in the light of the clinical data presented by the patient and the diagnostic or treatment options available. The guidelines issued are not intended to be prescriptive directions defining a single course of management and departure from the local guidelines should be fully documented in the patient's case notes at the time the relevant decision is taken.