Pyloric stenosis is a narrowing of the opening known as the pylorus, through which food and other stomach contents pass from the stomach to the small intestine. This narrowing occurs in newborns in the first two months of life and must be corrected immediately with surgery so the baby can digest milk and thrive.
The pylorus is surrounded by a circular muscle. When an infant has pyloric stenosis, the pyloric muscle is enlarged, narrowing the entrance to the small intestine. This enlargement produces a partial obstruction or blockage at the pylorus. Over a period of time, the pylorus becomes inflamed and swollen producing even further obstruction. Although infants are born with pyloric stenosis, symptoms usually are not noticed until 2 or 3 weeks after birth.
At first, pyloric stenosis may cause a mild backflow of food from the stomach to the mouth and mild vomiting. After the symptoms have been present for about a week, the vomiting progresses to projectile vomiting a condition in which the baby vomits so hard that the material vomited may actually go several feet through the air. Usually vomiting occurs within 30 minutes after feeding. After vomiting, the baby usually acts extremely hungry again and wants another feeding. Vomiting may be blood tinged if it is very forceful. The vomit usually does not have greeen bile in it because the blockage is above the area of bile production.
Other signs may be present: Constipation or small stools may be present because little food has been able to reach the intestine for further digestion.The baby may begin to lose weight and show signs of dehydration from excessive loss of fluids from the body. Signs of dehydration include a dry mouth, decreased wet diapers, no tears in the eyes when crying, and sunken eyes.The infant may shows signs of discomfort and may become sluggish or lethargic.The baby's abdomen may be distended or swollen. Just after feeding, before vomiting, gastric waves may be seen going from left to right over the stomach.A small, olive-sized mass may be felt through the skin in the upper right side of the abdomen.
Pyloric stenosis is a congenital defect, or condition present at birth. The exact cause of this condition is unknown. Pyloric stenosis affects more males than females (about 1 in 750 females and 1 in 150 males). It is the most common condition requiring surgery in the first 2 months of life. There is a 5% chance that a sibling of someone with pyloric stenosis will also have it and about a 25% chance that children of a mother with a history of pyloric stenosis will also have it.
This condition cannot be prevented. If there is a family history of pyloric stenosis, a new baby should be closely watched for any symptoms.
The healthcare provider will do a physical exam and take a full history. The healthcare provider may ask such questions as: When did symptoms start?How much has the baby been drinking at each feeding, or how long does he or she nurse at each feeding?How much time elapses after a feeding before the baby vomits?Does the vomit come out gently down the baby's face or come out with force, as with projectile vomiting?What does the vomit look like? Is there any bile?
The healthcare provider may be able to feel a small mass in the upper right side of the baby's abdomen. A blood chemistry test may reveal a salt imbalance. A complete blood count (CBC) may reveal high hemoglobin and hematocrit counts, indicating dehydration. An abdominal ultrasound usually confirms the diagnosis of pyloric stenosis. Sometimes, x-rays of the upper gastrointestinal tract, called an upper GI series, may be done.
If treatment is prompt, there are usually no long-term side effects from pyloric stenosis. Recovery depends on the general health of the infant and he or she was diagnosed and treated.
There are no direct risks of pyloric stenosis to others. This is not a contagious condition, but it can run in families.
The treatment of choice for pyloric stenosis is a surgical procedure known as a pyloroplasty. Prior to surgery the first concern is to rehydrate the infant with intravenous fluids. A nasogastric tube may also be inserted through the nose and down into the baby's stomach to remove gastric juices prior to and during surgery. After general anesthesia is given, the surgeon makes an incision down to the mucosa lining of the pylorus and across it. This opens up the narrowed pylorus.
There may be side effects from any surgery including risk of bleeding, infection, and even death. Any surgery in the abdomen can cause adhesions, which are bands of tissue that develop during healing and can keep internal organs from moving freely within the abdomen. Infrequently, adhesions can cause blockages in the intestines if they are in a place that allows them to compress part of the intestine. This can occur many years after the surgery. Anesthesia may cause stomach upset or allergic reactions.
Usually an infant can start small feedings of clear liquids once the intestines start moving well again. This may be as soon as 4 to 6 hours after surgery. The baby will progress to formula or breast milk during the course of the next few days. A baby may need to stay in the hospital for a few days to continue IV fluids and to slowly progress to oral feedings. The chances of full recovery after surgery are excellent. Sometimes continued vomiting may occur after surgery, if symptoms progressed to severe dehydration and malnutrition before surgery. In this case, intavenous fluids may be continued until vomiting subsides.
Once the condition has been treated and an infant has recovered from surgery, there may be no need for monitoring. If vomiting continues or symptoms recur, it is important to contact the healthcare provider.
Mayo Clinic Family Health Book, David E. Larson, 1996
Current Pediatric Diagnosis and Treatment, Hathaway, Hay, Groothuis, Paisley, 1993.