<prompt> A most common complication of sliding hernia is -Esophagitis due to continuous refluxPneumoniaHemorrhagePerforation  <response>: There are 4 types of a hiatal hernia Type I: Sliding hernia most common type 70 - 80 Type II: Paraesophageal or rolling hernia Type III: Mixed Type IV: These hernias are distinguished by the presence of other abdominal viscera within the defect i.e. momentum, transverse colon. Type I or Sliding hiatal hernia This is characterized by upward dislocation of the cardio-esophageal junction into the posterior mediastinum. Type II or Rolling Paraesophageal a hernia The cardio-esophageal junction is undisplaced The whole or pa of stomach herniates into the thorax immediately adjacent and to the left of the undisplaced cardio-esophageal junction. Since the normally located gastroesophageal junction functions normally in most of these hernias, reflux is uncommon. 