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Plyoric stenosis


What is pyloric stenosis?

The lower portion of the stomach that connects to the small intestine is known as the pylorus. In pyloric stenosis, the narrowing of the pylorus (through which food passes to enter the small intestine) has occurred as a result of the muscles in the pylorus becoming thickened and enlarged. As a result of this narrowing, eventually food is prevented from moving from the stomach to the intestine.

What are the causes of pyloric stenosis?

It is not known what the causes of pyloric stenosis are and there is nothing that can be done to prevent it from occurring. It is more likely to occur with your first baby and occurs four to six times more frequently in males than in females. There is an increased risk of pyloric stenosis occurring in siblings and any children of affected persons. All young infants are however, at risk.

How common is it?

Pyloric stenosis is fairly common. It occurs in one in every 150 males and one in every 750 females.

What are the signs and symptoms of pyloric stenosis?

The most common symptom in a baby with pyloric stenosis is vomiting large amounts of breast milk or formula soon after a feed. Vomiting usually starts gradually but as the pylorus becomes tighter, vomiting becomes projectile or forceful. The vomit is usually yellow and sometimes curdled in appearance.

Occasionally small brown specks of old blood may be seen in the vomit. Vomiting should not be green (bile—stained). If it is seek medical help urgently.

Even though vomiting usually begins at three weeks of age it can start as early as one week or as late as five months.

After vomiting your baby is usually hungry again and wants another feed. Prolonged vomiting may lead to weight loss or inadequate weight gains, dehydration (because your baby is not getting enough fluid), and constipation as a result of little or no food passing through the stomach to the intestine.

The signs of dehydration include: lethargy, nappies not as wet as usual and less frequent (babies normally have six to eight wet nappies a day), dry mouth and tongue, sunken eyes and the fontanelle, the soft spot on the top of the head, is more sunken than normal.

How is it diagnosed?

The diagnosis is made mostly from the child's medical history and physical examination.

This includes the pattern of feeding and vomiting, colour of the vomit, any weight loss or failure to gain weight and any signs of dehydration. The thickened pyloric muscle may also be felt, especially during feeding, as a small hard lump on the right side of the baby’s stomach. An ultrasound, like the ones used in pregnancy, may sometimes be performed to confirm the diagnosis by showing the thickened pyloric muscle.

Other tests that may be done include a barium swallow, endoscopy and blood tests to evaluate dehydration, which often also reveal an electrolyte imbalance.

What is the treatment required?

An operation called a pyloromyotomy performed under a general anaesthetic is needed to treat pyloric stenosis.

A pyloromyotomy is where the surgeon cuts through the muscle fibres of the enlarged pyloric muscle in order to widen the opening allowing the milk to move through into the intestine.

Before the operation

Your baby may be in hospital a day or two before the surgery. Before surgery can take place, intravenous fluids (IV) will usually be required to correct any dehydration and electrolyte imbalance that may be present as a result of continual vomiting.

Once your baby is rehydrated and their electrolytes are at a normal level, surgery can then be performed. All babies will also have a tube passed through their nose into their stomach (called a naso-gastric or NG tube). This tube allows air and secretions to drain out of the stomach reducing your baby’s vomiting. Usually the NG tube will be left on free drainage to allow air and secretions to drain out of the stomach. Regular aspiration of the NG tube (syringing of fluid out of the stomach) may also be ordered by the surgical team looking after your baby.

Most babies will not be allowed to drink at all once they come to hospital. However, if you are breastfeeding your baby you may still be able to give your baby a comfort feed. Only a small amount is recommended to help settle your baby. You will otherwise be encouraged to express regularly to maintain your milk supply.

Once a time has been determined for surgery, your baby will not be allowed to have anything further to drink orally for at least four hours before surgery.

The operation

Your baby will be away from the ward for about two hours. This includes giving the anaesthetic, performing the operation and then waking up in the recovery room.

Most doctors will allow you to be with your baby while they go to sleep. Once your baby is asleep, they will be taken to the operating theatre for the procedure and you will asked to wait in the parent's lounge.

Afterwards your baby will be taken to the recovery room, where they will have their observations—heart rate, breathing, and oxygen levelsmonitored. In most cases you will be able to hold your baby fairly soon after they arrive in recovery. Some babies are very drowsy for a few hours after the anaesthetic and others are wide awake. They may also be cranky and sometimes feeling nauseous.

After the operation

A nurse from the ward will be with you in the recovery room to escort you and your baby back to the ward following surgery.

Regular observations including temperature, heart rate, breathing and sometimes their level of oxygen will be taken to ensure your baby is recovering from the anaesthetic. An assessment of your baby’s pain will be made regularly and pain relief will be given as required and as ordered by the surgical team looking after your baby. It is likely your baby will experience some discomfort after surgery. Please let the nurses know if you do think your baby is in any pain.

Your baby will have a small wound on their tummy covered by a dressing that will also be checked regularly by the nurses. They will not usually be allowed to commence oral fluids for a few hours after surgery. This depends on your baby and your doctor. Your baby however will continue to have IV fluids running.

Once your baby can resume feeding they will begin on small frequent feeds. The amount is gradually increased as they tolerate it until they are back to a normal feeding pattern. The rate of IV fluids will decrease as your baby’s oral intake increases and is tolerated. Once your baby is tolerating feeds, IV fluids will stop.

It is normal for babies to still have small vomits after the surgery because of the swelling at the surgical site of the pyloric muscle. This usually settles gradually over a few days.

Going home

If your baby is tolerating feeds and having enough fluids to drink then you can normally go home between 24 and 48 hours following surgery.

You will be given an appointment for a review by your doctor. It is very important that you attend this follow up appointment to check that your baby has recovered without any complications and the wound has healed.

It may be necessary to continue to give your baby regular pain relief at home for a few days. Your doctor will suggest the best alternatives which may include paracetamol or nurofen.

The dressing on your baby’s tummy needs to be kept clean and dry. The steri-strips that are placed over the incision should be left in place and removed according to the instructions of your surgeon.

When to come back

Your child should be reviewed by a doctor if:

  • they have a red and/or swollen stomach around the wound(s)
  • the surgical site is oozing
  • they have a fever
  • they fail to gain weight or have lost weight
  • they are unsettled with pain relief, feeding or comforting
  • they are unusually sleepy and unable to stay awake for regular feeds

Circumstances when you should seek urgent medical advice:

  • signs of dehydration
  • persistent or projectile vomiting with feeds
  • respiratory difficulties.

How to seek urgent medical advice

To ensure your child receives the best possible care in an emergency, you should call 000 or go to your nearest Emergency Department. If you have any concerns or questions please contact your doctor.

If at any time during your child’s hospitalisation you have questions regarding treatment, or you are unsure of anything concerning your child, please ask to speak to the nurse or the doctor caring for your child.

Contact Mater Children’s Private Brisbane

Salmon Building,

Raymond Terrace,

South Brisbane QLD 4101

Telephone: 07 3163 8111


Mater acknowledges consumer consultation in the development of this patient information.
Mater Doc Num: PI-CLN-470032
Last modified 28/4/2020.
Consumers were consulted in the development of this patient information.
Last consumer engagement date: 01/10/2019
For further translated health information, you can visit healthtranslations.vic.gov.au/ supported by the Victorian Department of Health and Human Services that offers a range of patient information in multiple languages.
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