The evaluation of pyloric stenosis begins with a history and physical examination.

Physical findings in an infant with pyloric stenosis include:

• Abdominal swelling
• A firm lump that can be felt in the upper abdomen:
• About the size of an olive
• Signs of dehydration

Signs of dehydration include:

• Pale, dry skin
• Dry eyes and mouth
• Sunken eyes
• Sunken fontanelle
• Rapid pulse
• Lethargy:
• Excessive sleepiness
• Decreased urination
• Urinating less than 3 times over 24 hours

Testing is necessary to make the diagnosis of pyloric stenosis.

Tests that may be used to evaluate pyloric stenosis include:

• Complete blood count
• Serum electrolytes
• Upper GI series
• Can detect a narrowed pylorus
• Ultrasound of the abdomen