A woman in her late 80s visited a local physician complaining of nausea, loss of appetite, and constipation. She was referred to our hospital for detailed examination. Computed tomography (CT) revealed that the entire stomach, pancreas, spleen, transverse colon, and small intestine were prolapsed into the mediastinum and left thoracic cavity through the esophageal hiatus, which was dilated. Moreover, the small intestine was narrowed at the hiatus and dilated in the abdominal cavity, presenting ileus. After diagnosing type IV esophageal hiatal hernia with upside-down stomach and starting conservative treatment, the ileus improved and oral intake was resumed. Subsequent CT showed continued prolapse of the pancreas, spleen, transverse colon, small intestine, and entire stomach, but CT taken 5 years earlier had shown similar findings of prolapse. Thus, we decided not to perform surgery and instead opted for close follow-up after discharge. The patient is well without any symptoms of obstruction as of 1.5 years after discharge.