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Pyloric Stenosis - Information for parents

Patient information A-Z

What is pyloric stenosis?

Pyloric stenosis is a condition that can affect babies in the first months of life. Pyloric stenosis is a narrowing (‘stenosis’) of the exit from the stomach. The narrowing is caused by a thickening of the muscle. Food is therefore prevented from leaving the stomach by the normal route and so the baby vomits. The vomiting may be forceful (‘projectile’). Your baby may want to feed after vomiting and may not appear unwell at first. However, as you baby continues to vomit, your baby can become dehydrated, with less wet nappies than usual, and may become lethargic.

How is pyloric stenosis diagnosed?

  • The doctor will want to examine your baby which will include feeling your baby’s stomach. This examination is sometimes easier whilst your baby is feeding (this is called a ‘test feed’). During the examination the doctor is feeling for a thickened muscle which feels like a small hard lump.
  • Often babies will need to have an ultrasound scan which is similar to the scan that pregnant mothers have.
  • Blood tests will also be needed.

How is pyloric stenosis treated?

Your baby will need to have an operation which will be performed by a surgeon who specialises in small babies.

Before the operation can take place your baby’s dehydration will need to be resolved. Your baby will therefore have a ‘drip’ and be given fluids into a vein. These fluids will provide your baby with all the sugars and salts needed to keep your baby well. The amount of dehydration will be measured by regular blood tests being taken. To ensure the operation is safe for your baby, it will only take place once your baby’s blood tests are all normal. In some cases this may take a few days.

To prevent your baby from having continued vomiting (which would prevent blood tests returning to normal) your baby’s stomach must be kept empty. Your baby will therefore not be allowed to feed before the operation. A tube will also be passed through your baby’s nose into his/her stomach (called a nasogastric or NG tube). This tube allows all the secretions produced in the stomach to be removed.

The operation

The operation is needed to correct pyloric stenosis is called a ‘pyloromyotomy.’ During the operation the surgeon will ‘split’ the muscle at the bottom end of the stomach by making a cut into it. This widens the exit from the stomach to allow food to pass through.

Sometimes the muscle will be accessed by a small incision (cut) being made near the baby’s umbilicus (belly button) or, occasionally, the cut being made higher on the babies abdomen (tummy). Alternatively, the muscle will be accessed by laparoscopic (‘key hole’) techniques. Your surgeon will talk to you about which approach is planned for your baby. The wound will be closed with dissolvable stitches under the skin so after the operation only a small scratch is seen. There may also be paper strips called ‘steri strips’ applied.

You will be able to accompany your baby to the operating department and be with him/her in the recovery room after the operation until they are able to return to the ward.

After the operation

Many babies still vomit for a while after the operation when they start feeding again and this can take a few days or weeks to gradually settle. As the vomits are usually only small, your baby will not need to stay in hospital for all this time but will need to stay, and still have a drip, until they are taking enough feeds to keep hydrated. This is usually one to two days after the operation.

Your baby will be able to have pain killing medicine to reduce any soreness after the operation.

What are the complications of a pyloromyotomy?

Complications from this operation are rare. Rare complications include:

  • Bruising
  • Infection
  • Bleeding
  • Protrusion of tissue through the wound. This is rare but when it occurs a swelling or lump is seen over or close to the scar. As some swelling after any surgery is common it is important that this general swelling is not confused with protrusion of tissue through the wound. If you are unsure your child’s surgical team or GP will be able to review and discuss this with you. If protrusion of tissue through the wound does occur further surgery will be required.
  • Perforation to the stomach or surrounding organs
  • Inadequate myotomy; that is; inadequate splitting of the muscle


During your child’s hospital visits your child will need to be examined to help diagnose and to plan care. Examination may take place before, during and after treatment, is performed by trained members of staff and will always be explained to you beforehand. A chaperone is a separate member of staff who is present during the examination. The role of the chaperone is to provide practical assistance with the examination and to provide support to the child, family member/carer and to the person examining.

Discharge advice

  • It is important to keep the wound clean and dry. Nappies should be changed as soon as they are wet. Your baby can have sponge washes but no baths for five days. This is to prevent infection.
  • It is important to observe the wound for signs of infection (for example redness, swelling, fever). If any signs of infection are noticed you should contact your GP.
  • It may be necessary to continue to give your baby some pain killing medicine at home and your nurse will discuss this with you.
  • Your health visitor will have been made aware of your baby’s admission and diagnosis. It is important that your baby is weighed weekly for at least six weeks as he/she will have lost some weight through having pyloric stenosis. However, within six weeks, most babies will have regained this.

Follow up

Your baby requires review at approximately six to eight weeks after discharge. The review is to check that your baby has progressed without complications, is gaining weight and the wound has healed satisfactorily. The review may take place at Addenbrookes, at your local hospital or via your GP practice. Where review takes place will depend on a number of factors such as the presence of gastro-oesophageal reflux and degree of weight loss. If your babies follow up appointment is due to take place at Addenbrookes Hospital, you will receive a letter regarding the exact date and time. If you cannot attend your appointment, and so need this to be re-arranged, it is essential that you inform us so an alternative appointment can be arranged.

If you have any further questions please do not hesitate to ask the staff looking after you and your baby. We will be happy to help.

Contact numbers

Nurse specialist team: 01223 586973…….

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Contact us

Cambridge University Hospitals
NHS Foundation Trust
Hills Road, Cambridge

Telephone +44 (0)1223 245151