Pyloric stenosis: Symptoms, causes, and treatment Health ConditionsHealth ConditionsAlzheimer's & DementiaAnxietyArthritisAsthma & AllergiesBreast CancerCancerCardiovascular HealthCOVID-19Dermatology & SkincareDiabetesEnvironment & SustainabilityExercise & FitnessEye HealthHeadache & MigraineHealth EquityHIV & AIDSHuman BiologyInflammatory Bowel DiseaseLeukemiaLGBTQIA+Men's HealthMental HealthMultiple Sclerosis (MS)NutritionParkinson's DiseasePsoriasisSexual HealthWomen's HealthDiscoverNewsLatest NewsOriginal SeriesMedical MythsHonest NutritionThrough My EyesNew Normal HealthPodcastsHow to understand chronic painWhat is behind vaccine hesitancy?The amazing story of hepatitis C, from discovery to cureNew directions in dementia researchCan psychedelics rewire a depressed, anxious brain?Why climate change matters for human healthToolsGeneral HealthDrugs A-ZHealth HubsHealth ToolsBMI Calculators and ChartsBlood Pressure Chart: Ranges and GuideBreast Cancer: Self-Examination GuideSleep CalculatorHealth ProductsAffordable Therapy OptionsBlood Pressure MonitorsDiabetic SuppliesFitness TrackersHome GymsGreen Cleaning ProductsHow to Shop for CBDQuizzesRA Myths vs FactsType 2 Diabetes: Managing Blood SugarAnkylosing Spondylitis Pain: Fact or FictionConnectAbout Medical News TodayWho We AreOur Editorial ProcessContent IntegrityConscious LanguageNewslettersSign UpFollow UsMedical News TodayHealth ConditionsDiscoverToolsConnectSubscribe Pyloric stenosis Symptoms and treatmentMedically reviewed by Carissa Stephens, R.N., CCRN, CPN — By Oladimeji Ewumi on July 14, 2022Pyloric stenosis is a rare condition that occurs when the passage between the stomach and the small intestine narrows. It typically occurs in infants and can cause an obstruction, leading to projectile vomiting, abdominal cramps, dehydration, and hunger. Experts estimate that pyloric stenosis affects 2–5 in every 1,000 births. They also report that it usually affects infants under 6 months of age and is less common in older children. Without treatment, pyloric stenosis may affect growth and development. This article outlines the causes and symptoms of pyloric stenosis, along with information on diagnosis and treatment. What is pyloric stenosis Share on Pinterestskaman306/Getty ImagesPyloric stenosis is a rare condition that occurs when the pylorus, a muscular valve that sits at the bottom of the stomach, thickens. This causes the pylorus to narrow. Typically, the pylorus opens and closes to allow food through to the small intestine during digestion. When pyloric stenosis develops, this cannot happen as it should. Food and fluids cannot get through easily, so the body cannot digest and absorb them. Although this condition can occur anytime from birth onward, it usually develops within 2–8 weeks of age. Symptoms of pyloric stenosis Babies with pyloric stenosis often have no symptoms at birth. When they do develop, symptoms can include:Projectile vomiting: Initially, a baby with pyloric stenosis may vomit a little, but as the pylorus thickens, the vomiting becomes forceful. This means the vomit can travel several feet across the room from the baby’s mouth.Abdominal cramps: Before the baby vomits, a parent or caregiver may notice wave-like ripples in the baby’s upper abdomen immediately after eating. This is because the stomach muscles have to do more work than usual to push food into the small intestine.Dehydration: Frequent vomiting can cause a loss of water, leading to dehydration. Dehydration can happen quickly in babies and can become life threatening. A dehydrated baby may have few wet diapers, cry without tears, or become lethargic.Constant hunger: A baby with a narrow pylorus may always feel hungry, especially after throwing up, because they are not keeping milk or food down.Constipation: Infants with pyloric stenosis can have difficulty emptying their bowels since a reasonable quantity of food and water is not reaching the small intestine.Weight loss: Infants with pyloric stenosis can have problems gaining and maintaining weight. When to seek help A person should contact a doctor as soon as possible if a baby has any of the following signs and symptoms:projectile vomitinglack of energyweight lossless frequent urinationfewer bowel movements or constipation If the baby cannot keep any food or water down or shows signs of dehydration, dial 911 or the number of the nearest emergency department. Signs of dehydration in infants include:sunken eyesexcessive sleepinesscrying without tearscool or wrinkled skindiscolored hands and feeta sunken soft spot on the top of the head Causes and risk factors for pyloric stenosis Healthcare experts do not know what causes pyloric stenosis but have identified certain risk factors that may increase the likelihood. These include:Family history and genetics: Babies in families with a history of pyloric stenosis may have a higher chance of developing the condition. Research suggests that siblings have a 20-fold increased risk of developing pyloric stenosis. In identical twins, the risk increases 200-fold.Sex: Male infants are 4 times more likely to have pyloric stenosis than females.Firstborn infants: Pyloric stenosis is more common among firstborn infants, accounting for 30–40% of all cases. Scientists are not sure why this is.Race: According to the Centers for Disease Control and Prevention (CDC), pyloric stenosis is more common in white infants and less common in non-Hispanic Asian and non-Hispanic Black infants.Smoking: Smoking during pregnancy can double the risk of having a baby with pyloric stenosis.Antibiotic use: Ingesting certain types of antibiotics during their first 2 weeks of life can increase an infant’s chance of developing pyloric stenosis. This includes oral azithromycin and erythromycin.Bottle feeding: According to an older 2012 study, bottle-fed babies may be 4.6 times more likely to have pyloric stenosis than those not bottle-fed. However, the researchers could not determine why this might be the case. Diagnosing pyloric stenosis If an infant shows any signs or symptoms that could indicate pyloric stenosis, their caregiver should immediately contact a pediatrician. The pediatrician will perform a physical examination to check if an abdominal mass around the size of an olive is present in the child’s upper abdomen. They may also order other tests, including:Blood tests: These may confirm dehydration or an electrolyte imbalance.An abdominal ultrasound: This can show clear images of a thickened pylorus muscle.An upper gastrointestinal series: For this test, a baby drinks a barium liquid before having a special stomach X-ray. Treatment for pyloric stenosis The gold standard treatment for pyloric stenosis is a surgical procedure known as Ramstedt’s pyloromyotomy. This widens the space inside the pylorus, allowing food and fluids to pass through more easily. Ramstedt s pyloromyotomy procedure Before the surgery, a healthcare professional will test the baby’s blood to check they have healthy fluid and electrolyte levels. If they do not, the baby will receive IV fluids. Next, a medical professional will administer general anesthesia, so the baby feels no pain. Then a pediatric surgeon will begin the surgery. Surgeons can perform a pyloromyotomy in one of two ways: laparoscopically, which is minimally invasive, and through open surgery. In a laparoscopic pyloromyotomy, the surgeon will make three small incisions and use a camera to see inside the abdomen. They then use small tools to cut the muscle around the pylorus. In an open pyloromyotomy, the surgeon makes a bigger incision on the right side of the stomach and cuts the pylorus. The surgery usually takes about 30 minutes. After surgery Around 6 hours after surgery, the infant can begin having small amounts of food. These amounts can gradually increase as the baby tolerates it. The baby will usually go home after 1–2 days in the hospital. Healthcare professionals will monitor the baby for any postoperative complications during this period. After going home, they will need some special care while they recover. This involves:feeding as usual in the case of breast- or chestfeedingfeeding the baby no more than 3 ounces of formula every 3 hours for the first 3 days after surgery, slowly increasing the amount after this periodcaring for the incision wound, keeping it clean and dryavoiding full baths for 2 days, giving sponge baths insteadgiving the baby acetaminophen to reduce pain if the doctor says this is okay Complications of pyloric stenosis Without treatment, pyloric stenosis can cause the following complications:Hypovolemic shock: A delayed diagnosis can lead to an emergency where the heart cannot pump sufficient blood to major organs due to severe dehydration.Hematemesis: This is when a person throws up blood. Gastrointestinal irritation can upset the stomach’s mucosal lining, resulting in mild bleeding in the stomach.Jaundice: This is a buildup of bilirubin in the body, causing a yellowish coloration of the eyes and skin. This may be due to low levels of hepatic glucuronosyl transferase in the blood. Surgery for pyloric stenosis also involves a few potential complications, such as infection. However, the benefits vastly outweigh the risks, and most babies recover quickly with no adverse outcomes. Speak with a doctor if a baby develops any of the following after surgery:surgical wounds that are inflamed, swollen, bleeding, or leaking pusa fevercontinued vomiting after most mealsa swollen belly Frequently asked questions Here are answers to some common questions about pyloric stenosis. Will pyloric stenosis go away on its own No, pyloric stenosis cannot get better on its own. It requires treatment from a doctor. Can pyloric stenosis affect adults According to a 2018 review, pyloric stenosis occurs very rarely in adults. Sometimes it is idiopathic, meaning the cause is unknown. At other times, it can appear alongside other medical conditions such as ulcers, gastrointestinal tumors, or postoperative adhesions. What is the long-term outlook for an infant with pyloric stenosis If untreated, pyloric stenosis can cause severe complications. However, the outlook for infants who do receive the surgery is generally good. Most make an excellent recovery, and very few experience any long-term problems due to the condition. Summary Pyloric stenosis is a rare condition that typically affects infants below the age of 6 months. It occurs when the pylorus, the muscular valve at the bottom of the stomach, thickens. Infants with pyloric stenosis may not appear sick at first, but as the pylorus narrows, it becomes more difficult for food and water to pass through. Symptoms of pyloric stenosis include projectile vomiting, stomach cramps, constipation, and dehydration. If someone is concerned a child may have pyloric stenosis, they should talk with a doctor immediately. A person with pyloric stenosis needs surgery to correct the condition and improve digestive function. Last medically reviewed on July 14, 2022Emergency MedicineGastroIntestinal / GastroenterologyPediatrics / Children's HealthParenthood06 MonthsToddler 13 sourcescollapsedMedical News Today has strict sourcing guidelines and draws only from peer-reviewed studies, academic research institutions, and medical journals and associations. We avoid using tertiary references. We link primary sources — including studies, scientific references, and statistics — within each article and also list them in the resources section at the bottom of our articles. You can learn more about how we ensure our content is accurate and current by reading our editorial policy.After your child's surgery for pyloric stenosis. (n.d.). https://www.saintlukeskc.org/health-library/after-your-childs-surgery-pyloric-stenosisBanda, F. M., et al. (2017). An unusual surgical cause of pyloric stenosis in an 8-month-old infant. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6369598/Chalya, P. M., et al. (2015). Infantile hypertrophic pyloric stenosis at a tertiary care hospital in Tanzania: A surgical experience with 102 patients over a 5 year period. https://bmcresnotes.biomedcentral.com/articles/10.1186/s13104-015-1660-4Eberly, M. D., et al. (2015). Azithromycin in early infancy and pyloric stenosis [Abstract]. https://publications.aap.org/pediatrics/article-abstract/135/3/483/75511/Azithromycin-in-Early-Infancy-and-Pyloric-StenosisGarfield, K., et al. (2022). Pyloric stenosis. https://www.ncbi.nlm.nih.gov/books/NBK555931/Hassan, S. M., et al. (2018). Adult idiopathic hypertrophic pyloric stenosis: A common presentation with an uncommon diagnosis. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5906761/Islas-Dominguez, L. P., et al. (2018). Hypertrophic pyloric stenosis in pre-term infants: A case report. https://www.sciencedirect.com/science/article/pii/S0185106317300057Krogh, C., et al. (2012). Bottle-feeding and the risk of pyloric stenosis. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3457615/Ndongo, R., et al. (2018). Infantile hypertrophic pyloric stenosis: A 4 year experience from two tertiary care centers in Cameroon. https://bmcresnotes.biomedcentral.com/articles/10.1186/s13104-018-3131-1Pyloric stenosis. (2020).https://www.gosh.nhs.uk/conditions-and-treatments/conditions-we-treat/pyloric-stenosis/Pyloric stenosis. (n.d.). https://www.hopkinsmedicine.org/health/conditions-and-diseases/pyloric-stenosisRacial and ethnic differences in the occurrence of major birth defects. (2018). https://www.cdc.gov/ncbddd/birthdefects/features/racialethnicdifferences.htmlTaghavi, K., et al. (2017). The treatment of pyloric stenosis: Evolution in practice [Abstract].https://pubmed.ncbi.nlm.nih.gov/29148193/FEEDBACK:Medically reviewed by Carissa Stephens, R.N., CCRN, CPN — By Oladimeji Ewumi on July 14, 2022 Latest newsWhat sets 'SuperAgers' apart? Their unusually large neuronsOmega-3 may provide a brain boost for people in midlifeSeasonal affective disorder (SAD): How to beat it this fall and winterCDC: Monkeypox in the US 'unlikely to be eliminated in the near future'Why are more women prone to Alzheimer's? New clues arise Related CoverageWhat are the causes of projectile vomiting?Medically reviewed by Saurabh Sethi, M.D., MPH Projectile vomiting is when vomit is forcefully expelled. In infants this can be normal, but in adults it may have some more serious causes.READ MOREWhat is laryngomalacia?Medically reviewed by Nicole Leigh Aaronson, MD, MBA, CPE, FACS, FAAP Laryngomalacia is the most common cause of stridor, or noisy breathing. It affects a child's larynx, or voice box. Learn more here. READ MORE9 of the best deodorants for kids in 2022Medically reviewed by Cynthia Cobb, DNP, APRN, WHNP-BC, FAANP Some children may start to have body odor from ages 9 or 10. Deodorants for kids may help. Learn about the best kids deodorants here.READ MORE