All of the following are FALSE in case of hyperophic pyloric stenosis, EXCEPT:

In hyperophic pyloric stenosis, the musculature of the pylorus and adjacent antrum is grossly hyperophied, the hyperophy being maximum in the pylorus itself. It occur in approximately 3 in 1000 live bihs and is the most common surgical cause of vomiting in infancy. Males are affected more commonly as compared to females and characteristically the first born male child is affected. The condition is most commonly seen at 4 week after bih ranging from 3rd week to 7th week in rare occasions. Only 20% of infants are symptomatic from bih. The diagnosis of pyloric stenosis usually can be made on clinical examination by palpation of the typical "olive" in the upper quadrant and the presence of visible gastric waves on the abdomen. In healthy infants when palpation is difficult, feeding can help in the diagnosis. After feeding peristalsis waves may be visible. After the infants vomits, the abdominal musculature is more relaxed and the mass is easier to palpate. "When the olive cannot be palpated, USG can diagnose the condition accurately in 95% of patients". Surgical operation done for hyperophic pyloric stenosis is Fredet- Ramstedt pyloromyotomy. (In it the pyloric mass is split without cutting the mucosa) Ref: Schwaz 9/e, Page 1425; Bailey & Love 25/e, Page 78; Rudolph's Pediatrics 21/e, Chapter 17