Pyloric Stenosis

What is pyloric stenosis?

The pylorus is the outlet of the stomach into the small intestine. Stenosis means a narrowing. Pyloric stenosis means a narrowed outlet of the stomach. It occurs in some new-born babies.

Food and drink pass down the gullet (oesophagus) into the stomach. Here it mixes with acid and is partially digested. The stomach then normally passes the food and drink into the small intestine to be fully digested and absorbed into the body.

A narrowed or blocked outlet from the stomach (pyloric stenosis) can lead to a serious illness unless it is treated.

What are the symptoms of pyloric stenosis?

Symptoms typically begin in a baby 2-4 weeks old who is otherwise healthy. In some cases symptoms can take up to two months to first start.

Vomiting - after a feed is the main symptom. The vomiting is often 'normal' and milk just dribbles down the front of the baby. Sometimes the vomiting is forceful and milk may be vomited quite a distance like a fountain. This is called 'projectile vomiting'.

The baby remains hungry and will usually feed well - only to vomit the milk back soon after feeding. The vomiting tends to get worse and worse over several days.

Little food or drink passes through the narrowed pylorus which gets narrower over time. Affected babies do not gain weight and are in danger of quickly becoming dehydrated (lacking in body fluid) and seriously ill if the condition is not treated.

What causes pyloric stenosis?

The muscle in the wall of the pylorus is abnormally thick. This causes the outlet from the stomach to become stenosed (narrowed). It is not known why this occurs. Boys are affected more commonly than girls.

Are any tests needed?

A doctor may examine the baby's tummy (abdomen) whilst they are feeding. A typical bulge next to the stomach can often be felt as the muscles in the stomach and pylorus contract. The diagnosis is confirmed if the bulge is felt. An ultrasound scan may be done if there is doubt about the diagnosis. This painless test is very reliable at detecting the thickened pylorus.

What is the treatment for pyloric stenosis?

Surgery - the traditional treatment
A small operation done under a general anaesthetic usually cures the problem. A small cut is made in the skin over the pylorus. The pylorus is found and the muscle in the pylorus is then cut. This allows the stomach outlet (pylorus) to widen into a normal size. These days the operation is often done by 'keyhole surgery'. This uses only a tiny cut to the skin to allow fine instruments into the abdomen to cut the pylorus muscle.

Before the operation a 'drip' is usually put in the baby's vein to give fluid and sugar. This prevents dehydration until normal feeding can resume.

The operation is usually totally successful. Normal feeds are started again shortly after the operation. Most babies recover quickly and have no further problems.

Medical treatment
Recently, it has been found that a medicine called atropine may cure the problem. For example, in one study, 22 babies with pyloric stenosis were given atropine medicine for several weeks. In 18 of the babies the pyloric stenosis cleared without the need for surgery. Atropine works by relaxing the muscles in the gut and stomach. Further research is needed to confirm the place of atropine in the treatment of pyloric stenosis.

References

• Dara A Kass and Richard Sinert Pyloric Stenosis Emedicine Article dated Feb 6 2006
• Sretenovic A et al Conservative treatment of hypertrophic pyloric stenosis in children Srp Arh Celok Lek 2004 Oct;132 Suppl 1:93-6
• Awahara H et al. Medical treatment of infantile hypertrophic pyloric stenosis: should we always slice the "olive"? J Pediatr Surg. 2005 Dec;40(12):1848-51
• Forfar and Arneils Textbook of Pediatrics. Edited by Campbell AGM and McIntosh N. 5th Edition 1998

© EMIS and PIP 2007   Updated: February 2007