Hypertrophic pyloric stenosis.

Hypertrophic pyloric stenosis is a gastrointestinal tract disorder common in infancy. The disorder causes projectile vomiting, weight loss, and fluid and electrolyte abnormalities. The problem can usually be diagnosed by clinical symptoms and manual detection of an enlarged pylorus. When the diagnosis cannot be confirmed by these methods, however, imaging studies are relevant. Until recently, plain radiographs and upper gastrointestinal contrast studies have been used to make the diagnosis, but ultrasonography is becoming the method of choice because it is highly accurate and lacks the ionizing radiation inherent in a radiologic procedure. Surgery provides a safe and effective treatment.