<prompt> Congenital pyloric stenosis causes: 1. Bilious vomiting 2. Non- bilious vomiting 3. Projectile vomiting 4. Non projectile vomiting 5. Forceful1,2 42,3,4 51,3 4All are seen  <response>: The vomiting in pyloric stenosis may or may not be projectile, however non bilious vomiting after feed is the characteristic feature. In about 10-15 of infants vomiting may contain blood. This bleeding is due to reflux esophagitis, a common association with hyperophic pyloric stenosis. Also know: Associated anomalies occur in 6-20 of patients. These includes esophageal atresia, Hirschsprungs disease, anorectal anomalies, and intestinal malformation. Ref: Nelson 17e, Page 1229. 