How is pyloric stenosis diagnosed?

Your healthcare provider will ask you several questions about your child's feeding habits and will then examine your child. During the physical exam, the healthcare provider may be able to feel an olive-sized lump (the thickened pyloric muscle) in your child's abdomen. If the thickened pylorus is felt, no further studies are needed.

If the thickened pylorus cannot be felt, an abdominal ultrasound may be done. During this examination, a probe is gently applied against the abdomen. The probe transmits sound waves through the body tissues, receives the echoes, and transforms them into diagnostic images. Often, the enlarged pyloric muscle can be seen on the ultrasound images.

In some cases, an upper gastrointestinal series must be done if the physical exam and abdominal ultrasound do not reveal any abnormalities. This test requires that your child drink a special liquid. This liquid can be seen on an X-ray as it travels through the stomach and small intestine. The pediatric radiologist will be viewing the X-ray while your child drinks the liquid to determine whether or not the liquid is able to move out of the stomach through the pylorus.

Last reviewed by a Cleveland Clinic medical professional on 12/22/2016.


  • Aspelund G, Langer JC. Current management of hypertrophic pyloric stenosis. Sem Ped Surg 2007;16:27-33.
  • Merck Manual. Hypertrophic Pyloric stenosis. Accessed 1/31/2017.

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