Diagnosis

Your doctor will start with a physical exam and questions about your baby's symptoms. If your baby is healthy, growing as expected and seems content, then testing usually isn't needed. In some cases, however, your doctor might recommend:

• Ultrasound. This imaging test can detect pyloric stenosis.
• Lab tests. Blood and urine tests can help identify or rule out possible causes of recurring vomiting and poor weight gain.
• Esophageal pH monitoring. To measure the acidity in your baby's esophagus, the doctor will insert a thin tube through the baby's nose or mouth and into the esophagus. The tube is attached to a device that monitors acidity. Your baby might need to stay in the hospital while being monitored.
• X-rays. These images can detect abnormalities in the digestive tract, such as an obstruction. Your baby may be given a contrast liquid (barium) from a bottle before the test.
• Upper endoscopy. A special tube equipped with a camera lens and light (endoscope) is passed through your baby's mouth and into the esophagus, stomach and first part of the small intestine. Tissue samples may be taken for analysis. For infants and children, endoscopy is usually done under general anesthesia.