Necrotising Enterocolitis

What is necrotising enterocolitis?

Necrotising enterocolitis (NEC) is a serious condition where the gut (intestine) becomes inflamed. If severe, the inflammation can cause a part of the intestine to rot away and burst, so that the contents of the guts can spill inside the tummy (abdominal) cavity. If the intestine bursts, it is called perforation, and is a very serious condition which must be treated urgently.

Who gets necrotising enterocolitis?

Most commonly this is a condition which affects newborn babies, and in particular babies who were born too early (premature babies). Around one in ten babies of very low birth weight (under 1500 g) will develop NEC. Most cases of NEC occur in premature babies, although occasionally it does develop in babies born after a normal length of pregnancy (full-term babies). NEC is becoming more common, which is a reflection of how many more babies survive being born very early.

What causes necrotising enterocolitis?

It is not entirely clear. It seems to be due to a mix of factors. Certainly it appears that the fact that the guts (intestines) haven't finished their full development is part of the problem. They may not work normally. It is likely that some type of infection is also involved, as is the type of feeding (particularly feeding with milk other than breast milk).

What are the symptoms of necrotising enterocolitis?

It can be quite difficult to diagnose NEC because some of the early symptoms and signs are quite common in very premature babies anyway, even those who do not have NEC. Possible symptoms include:

• Poor feeding.
• A swollen tummy (abdomen).
• A change to the colour of the tummy.
• Being sick (vomiting).
• Blood in the poo (stools) and a change in the appearance of the stools.
• The baby becoming more unwell with breathing problems, a change in heart rate and blood pressure, and difficulties keeping at a normal temperature.

What tests are needed?

Usually an X-ray of the baby's tummy (abdomen) will help with the diagnosis. Blood tests may also be useful. Occasionally other tests such as an ultrasound scan may be used.

What is the treatment for necrotising enterocolitis?

Resting the bowel

Many babies with NEC can be treated by resting the gut (intestines). Your baby would be fed by a tube into the veins to avoid anything going into the gut. Anything inside the gut is drained by suction from a tube going through the nose. Antibiotics are used to treat any infection present.

In some cases it may be necessary to place a drain into the tummy to drain out any fluid or poo which has collected outside the gut.

An operation

If NEC is not getting better with bowel-resting treatment, or if the symptoms are very severe, then an operation may be needed. Your baby will have a general anaesthetic. A cut is made in the tummy (abdominal) wall. This is called a laparotomy. Any damaged intestine is cut out. If possible, the ends of normal intestine are joined back together again. In some cases this is not possible and the open upper end of the intestine is sewn so it opens on to the tummy. The poo would then empty into a bag on the tummy wall. This is called a stoma. Usually at a future time when your child is well, another operation can be done to re-join the ends of the guts so that they can open their bowels normally and not into a bag.

After the operation, your baby will need ongoing intensive care as they recover, in a neonatal intensive care unit (NICU). The newly repaired gut will need to rest until they heal, so your baby would be fed through a tube into a vein. They may be on a ventilator to breathe for them. They will be on strong painkillers. Eventually, after about ten days or so, the bowel will be healed enough for them to be fed on milk again. The length of time this takes, however, is very variable and will depend on how premature your baby is, and how much of the bowel was damaged.

All operations and anaesthetics can be risky, and your specialists will explain to you in detail what these risks might be. If NEC is severe, however, the risk of not having the operation may be even greater than any risks involved in having it.

What is the outlook?

This is very variable. It depends on how premature your baby is, how unwell they become, and whether the gut has perforated. NEC is a very serious condition, and sadly some babies who develop NEC die from it. Overall about three out of four babies survive NEC. The outlook (prognosis) is best for those babies who recover from NEC without needing an operation.

In some cases, complications can develop after the operation. For example, scarring from the operation can stop the gut working. Infections can develop around the area treated at the operation. If a lot of the gut has been removed then it may not function very well even after it has healed. This may cause problems keeping the baby well nourished.

Can necrotising enterocolitis be prevented?

This is a developing area. More studies are needed to be sure. It appears that babies fed with breast milk are less likely to develop NEC. So where this is possible, breast milk is the ideal feed. Changing feeding regimes very slowly may also help. It may also be that treatment with probiotics can reduce the chances of a baby developing NEC. Probiotics are 'good' germs, which in theory can help fight harmful germs. However, more studies are needed to know if probiotics can help, and if so, what type and what dose should be used. Other studies are looking at whether treating babies with a protein called lactoferrin might help prevent NEC. Lactoferrin is a protein which is usually found in milk and which helps to fight infection.