University Hospital Southampton NHS Foundation Trust

Necrotising Enterocolitis

Necrotising Enterocolitis (NEC) is an inflammation of the bowel (intestines) that may damage the bowel to a variable extent. It usually causes a temporary intolerance of milk feeds but at its worse the bowel may be so damaged that parts of it actually die. NEC may affect just a small part of the bowel or, on occasions, the whole bowel may be affected.

It has a variable course ranging from feed intolerance and abdominal distension (swelling) to a sudden collapse of a baby who had previously been relatively well.

Symptoms of NEC include:

  • a tender tummy
  • blood in the stool
  • bile (green) vomiting
  • signs of generalised illness and infection, for example, increased apnoeas and bradycardias, low blood pressure.
  • occasionally a baby may become acutely and profoundly unwell and require extensive medical intervention.

Who is most likely to suffer from NEC?

NEC is a condition that is almost exclusively confined to newborn babies in the first days to weeks after birth. It is much more common in premature infants and particularly those who have a lot of other medical problems or who have been unwell prior to birth for example, if they have not been growing properly in the womb.

Occasionally bigger term babies may develop NEC. Again, problems in the womb or during birth may predispose such babies to NEC, as do some other problems like congenital heart conditions or abnormalities of the bowel.

How often does NEC occur?

Surveys suggest that ‘confirmed NEC’ occurs in around 3 in 10,000 babies. For babies admitted to Neonatal Units the figure is around 3 in 1000 babies. This is because those babies at risk are usually admitted to a Neonatal Unit because of their other problems for example, prematurity. The early symptoms of NEC are often rather non-specific therefore the diagnosis of ‘possible NEC’ is made in many more babies and treatment started in case the condition develops.

Why does Necrotising Enterocolitis occur and is it a serious condition?

Premature and other sick newborn babies have immature and fragile bowels. Why a certain baby develops NEC is often impossible to determine but we believe the interaction of many different factors may be involved.

It can be a serious illness. Some babies may lose some of their bowel because of it, for other babies, it may prove fatal.

What is the best course of treatment for NEC?

If a baby is suspected to be developing NEC or has definite evidence of NEC the following treatments may be started:

Stopping milk feeds – resting the bowel appears to help the bowel recover. Starting antibiotics to treat any infection – bacteria seem to play some part in the development of NEC and therefore antibiotics may help settle the process down. Intravenous feeding is required to keep the baby nourished while milk feeds cannot be given.

If the baby becomes generally unwell a number of other treatments may be necessary, for example, help with breathing, medication to help blood pressure.

X-rays and blood tests will be done to both confirm the diagnosis and monitor the response to treatment. Many babies who develop NEC recover with these ‘medical’ treatments.

However if an area of bowel dies or there is a perforation (hole) of the bowel further treatment may be necessary:

Are there options for further treatment?

Insertion of drain - A drain can be inserted into the baby’s abdomen to allow any free air or fluid to drain out. This is often performed in the first instance especially if the baby is too unwell for an operation, however an operation may still be necessary at a later point.

Laparotomy - An operation under general anaesthetic. The surgeon will aim to remove the part of bowel that has died and rejoin the two ends together (resection and anastomosis). Sometimes it may be very difficult to operate in the abdomen so a stoma (bowel opening onto the abdominal surface) maybe created. In this case the baby will need a further operation to rejoin the bowel together.

What are the risks?

About 50% of cases, where babies are referred for surgery with NEC, may end in fatality. This may be before an operation is done or sometime after. The risks of surgery are greater if your baby is very sick.

What happens after the operation?

Your baby will:

  • need help with breathing so will be connected to a ventilator.
  • be closely monitored and will be attached to various monitors.
  • be intravenously fed. A long line will probably be needed for intravenous feeding.
  • be given pain relief as necessary.
  • need blood products and other medications.

We will keep you fully informed of all developments in your baby’s care and explain things that are particularly relevant to your baby. Your baby will be under the shared care of a paediatric surgeon and neonatologist.

Caring for a stoma

If a stoma has been created we will teach you how to care for this. If your baby goes home with a stoma, support will be available in the community. Occasionally the stoma may retract into the abdomen or prolapse out, which may require further surgery.

When I can start milk feeds again?

The length of time for recovery is very variable but it is usually 10 days before milk is reintroduced. Because your baby is small and has suffered a problem with the bowel we prefer to use breast milk. There is a bank of donor milk if no maternal milk is available. The nurse looking after your baby will talk to you about this option. Sometimes it may be necessary to use a specially prepared formula milk.

If your baby has been referred from another hospital the length of stay in Southampton will depend on their recovery. We like to start milk feeds and be reasonably confident that further specialist care is not necessary before return to your original hospital. If a stoma has been created it will be necessary for your baby to return to Southampton at a later date for surgery to rejoin the bowel.

Are there any long term problems from Necrotising Enterocolitis?

Most babies who recover from NEC do not have further problems; but future problems are possible especially if there has been bowel perforation. These include:

  • NEC may recur
  • the wound may become infected or break down.
  • the bowel may narrow due to scar tissue either caused by damage to the bowel or at the operation site. This is called a stricture. If this occurs another operation will be necessary to remove this piece of bowel.
  • Sometimes if a lot of bowel has been removed this may cause problems with food absorption and therefore growth. Longer term intravenous feeding may be necessary (short bowel syndrome).


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