Your baby's doctor will start with a physical examination. Sometimes, the doctor can feel an olive-shaped lump — the enlarged pyloric muscle — when examining the baby's abdomen. The peristaltic waves in the baby's abdomen are another telltale sign of pyloric stenosis.

Your doctor might also recommend:

  • Blood tests to check for dehydration or electrolyte imbalance or both
  • Ultrasound to view the pylorus and confirm a diagnosis of pyloric stenosis
  • X-rays of your baby's digestive system, if results of the ultrasound aren't clear
Nov. 24, 2015
  1. Kliegman RA, et al. Pyloric stenosis and other congenital anomalies of the stomach. In: Nelson Textbook of Pediatrics. 20th ed. Philadelphia, Pa.: Elsevier; 2016. http://www.clinicalkey.com. Accessed Sept. 20, 2015.
  2. Olive AP, et al. Infantile hypertrophic pyloric stenosis. http://www.uptodate.com/home. Accessed Sept. 20, 2015.
  3. Delaney CP, ed. Pyloromyotomy for pyloric stenosis. In: Netter's Surgical Anatomy and Approaches. Philadelphia, Pa.: Saunders Elsevier; 2014. http://www.clinicalkey.com. Accessed Sept. 20, 2015.
  4. Odze RD, et al., eds. Neuromuscular disorders of the gastrointestinal tract. In: Odze and Goldblum Surgical Pathology of the GI Tract, Liver, Biliary Tract, and Pancreas. 3rd ed. Philadelphia, Pa.: Saunders Elsevier; 2015. http://www.clinicalkey.com. Accessed Sept. 20, 2015.
  5. AskMayoExpert. Suspected pyloric stenosis (pediatric). Rochester, Minn.: Mayo Foundation for Medical Education and Research.
  6. Davies BW. The vomiting infant: Pyloric stenosis. Surgery. 2013;31:622.