49.滿月嬰兒若於餵食後呈現噴射狀嘔吐，須懷疑幽門肥厚性狹窄（hypertrophic pyloric stenosis），下列有關 檢查及治療之敘述，何者最正確？
(A)確定診斷可借助腹部觸診發現右上腹橄欖狀硬塊、腹部超音波或上消化道攝影
(B)平躺腹部X光檢查可發現雙氣泡徵象（double bubble sign）
(C)嬰兒幽門肥厚性狹窄因屬腸胃道阻塞之一，通常屬於外科急症（surgical emergency）
(D)手術治療目前以幽門成形手術（pyloroplasty）為主

Initial Treatment:

• Hydration: Ensuring the baby is well-hydrated is crucial. If the baby is dehydrated, fluids are administered before surgery.
• Correcting Electrolyte Abnormalities: Addressing any imbalances in electrolytes (such as sodium and potassium) is essential.

Definitive Treatment:

• Pyloromyotomy: Surgery is the primary treatment for HPS. The procedure, called pyloromyotomy, involves making a longitudinal incision in the thickened outer muscle layer of the pylorus. The inner layers remain intact. This creates a wider channel for food to pass from the stomach to the intestines.