Pyloric hypertrophy is commonly seen in two conditions: 1. Congenital, which means that it is present at birth. This hypertrophy will be accompanied by a narrowing of the pylorus, so the affected child will often have recurrent spitting up, nausea, and vomiting. Treatment should begin with correction of the iatrogenic disorder, followed by surgery, which involves cutting open the pyloric muscle. This surgery is very effective and often restores the function of the pylorus. 2. Acquired. Pylorus hypertrophy due to repeated inflammation and erosion of the pylorus and other irritations can also produce the symptoms of stenosis. In this case, surgery is an option if it is not malignant, or treatment with a stent.