Understanding Pyloric Stenosis: Causes and Treatment Options

Pyloric Stenosis- well, hello! That is a rather difficult medical term and probably means nothing to anyone who hasn’t had to experience their baby suddenly developing projectile vomiting.

Alarm bells in my head start ringing when I consult on a baby, and the discussion goes like this:

Doctor: Hello, I am Dr Enrico. How can I help you today?

Parent: It is the strangest thing. My baby started to vomit after feeding a few days ago. I initially thought he had just overfed, but now he is projectile vomiting after every feed. Despite vomiting, he is hungry and once the vomiting is over, he is hungry again.

Doctor: How old is your baby now?

Parent: My baby is six weeks old.

Doctor: Have you noticed any other symptoms?

Parent: Not really.

Doctor: Ok. Take your baby through to my examination bed and let’s have a look.

Doctor: Your baby appears a bit dehydrated, and I can feel a little lump, probably the size of an olive, on the belly. Can you see that there are little ripples moving across your baby’s tummy? This is the peristalsis happening. In other words, the digestive muscles are contracting, and we are observing that. Given that there is nothing else to find, your baby’s age and with the history you have given me, I suspect that your baby may have Pyloric Stenosis.

Parent: Sorry, doctor, but I have never heard of Pyloric Stenosis. What is it?

It would be at this stage of the discussion that I would need to explain to the parent about the condition.

What is Pyloric Stenosis?

Imagine the gut as one long, sophisticated hosepipe. It has an opening at the mouth and another at the anus. Milk is taken in and follows the path down the throat, into the stomach, on to the small intestine, travels through the intestines, and the waste products are then pooped out.

This amazing journey takes place due to the contraction of muscles in the walls of the digestive tract. The muscles literally squeeze the food along from one section of the digestive system to the other. While one set of muscles is squeezing, the muscles in front of the food relax to allow the food to pass into the next section of the tract.

At the end of the stomach, leading into the small intestine, is a muscle that opens and closes called the pylorus. The muscle closes when milk (or food) is in the stomach being digested and then opens again to let the milk pass into the small intestine. This muscular opening can thicken, which causes the opening to narrow, making it impossible for the milk to pass through this point.

To break down the term correctly for you:

Pyloric refers to the pylorus

Stenosis means narrowing

You may even hear the term Hypertrophic Pyloric Stenosis. This is the full medical name. Hypertrophic means thickening. 

How common is Pyloric Stenosis?

Pyloric Stenosis is a fairly common condition in infants. It affects about 1 to 5 babies out of 1000. Pyloric Stenosis is more common in boys than in girls. This is a ratio of about four boys to every one girl.

Why did you say that my baby’s age is significant?

Pyloric Stenosis typically starts between four and eight weeks. Early onset is rare and we don’t generally see Pyloric Stenosis after the age of three months.

What are the typical symptoms of Pyloric Stenosis?

• Initially, vomiting may be infrequent.
• Over a couple of days, the vomiting becomes forceful after each feed (projectile).
• Babies remain hungry and will have a really good suck after a vomiting episode because their little tummies are empty and nothing is moving into the intestine to give them nourishment.
• There is no fever.
• You may notice wave-like ripples over your baby’s tummy. The muscles are trying to move the food out of the stomach, but the swollen pylorus is not allowing the food to move.
• Your baby will become dehydrated if the vomiting persists. Signs of dehydration would include dry nappies, no tears when crying, sunken fontanel, dry mouth, weakness and sunken eyes.
• Your baby may become constipated because food cannot reach the intestine.
• A baby that is vomiting up all its feeds will definitely lose weight.

How is Pyloric Stenosis diagnosed?

• Physical examination – The first step will be for your doctor to examine your baby for signs of Pyloric Stenosis. Much like the discussion between doctor and parent, symptoms will be considered.
• Ultrasound – Your doctor will most likely call for an ultrasound. Your baby will go to the X-ray department and an ultrasound will be performed. It is a simple test whereby a device is placed on the baby’s tummy and the radiologist will be able to see images of the baby’s pyloric muscle. A diagnosis is confirmed if this is enlarged.
• X-ray – This is not used as often as an ultrasound. A special X-ray that creates a video would allow the radiologist to follow the path of the liquid drunk by the baby. They will watch to see if the fluid enters the stomach and then whether it exits the stomach into the intestine. The radiologist will be able to see if the pyloric muscle is obstructing the flow of the liquid. If so, then a diagnosis of Pyloric Stenosis can be made.
• Blood tests – Your doctor may order blood tests to check your baby’s hydration.

Once we have a diagnosis of Pyloric Stenosis, what will the treatment be?

The most effective treatment for Pyloric Stenosis is surgery.

Before the surgery, your baby is likely to be admitted for intravenous fluids. This means that a drip will be put up and fluids will be given for about 24 to 48 hours, depending on how dehydrated your baby is.

A surgeon will perform an operation known as a pyloromyotomy. The surgeon will usually make three small holes in the belly. The surgeon will use one hole for a video camera and the other two for the instruments. The surgeon will cut into the thickened muscle and use an instrument to spread the muscle apart.

The pylorus will still be able to open and close, but the surgery loosens the muscle so that food can pass through easily again.

The only medication available for Pyloric Stenosis is a medicine called Atropine sulfate. This is certainly not the preferred treatment because it means that your baby has to stay in hospital for weeks on a drip to receive the medication and to be given nutrition until the vomiting settles. Being in the hospital for a long time comes with a whole new set of problems. This would only be considered if surgery were too dangerous in your baby’s specific case.

What happens after the surgery?

Most doctors will recommend that your baby remain in the hospital for at least 24 hours after the surgery. This will give the medical staff time to watch your baby carefully.

Feeding is likely to start about 12 to 24 hours after the surgery. This is usually in the form of clear fluids to start with, and thereafter milk. Your doctor will guide you on this.

Follow-up appointments with your healthcare professional will be important after the surgery to ensure that your baby is gaining adequate weight and meeting developmental milestones.

Conclusion

Pyloric Stenosis can be a tricky diagnosis initially. Parents of formula-fed babies often change formulas because they think their baby has an intolerance to the current formula. Breastfed parents consider overfeeding, excessive winds, reflux and so on as a cause for vomiting.

My advice would be to be aware of the typical signs:

• Age of the baby
• Frequency of the vomits
• Visible movement across the tummy
• AND MOST IMPORTANTLY- IF YOU, AS THE PARENT, ARE CONCERNED, PLEASE GET MEDICAL ADVICE.

Pyloric Stenosis can lead to severe dehydration and electrolyte imbalances. Over the long term, it can certainly cause malnutrition. The good news is that once the surgery is performed, it is very unlikely to recur. Baby will be back to full feeds and normal growth within a couple of days.

References:

1. https://my.clevelandclinic.org/health/diseases/4524-pyloric-stenosis-hps
2. https://www.sciencedirect.com/science/article/pii/S2213576625001356
3. https://www.mayoclinic.org/diseases-conditions/pyloric-stenosis/symptoms-causes/syc-20351416
4. https://pediatricsurgery.wustl.edu/patient-care/congenital-and-pediatric-conditions/pyloric-stenosis
5. https://www.rch.org.au/clinicalguide/guideline_index/Pyloric_stenosis/