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